Pin GitHub Actions to full-length commit SHAs (#26213)

## Summary

This PR pins GitHub Actions to full-length commit SHAs for improved
security and reproducibility and adds a 7 day cooldown to Dependabot
configuration for GitHub Actions. This work is described in more detail
at https://aka.ms/action-pinning.

## Why?

Pinning actions to commit SHAs prevents supply-chain attacks where a tag
could be moved to point to malicious code. This is a recommended
security best practice per the [GitHub Actions security hardening
guide](https://docs.github.com/en/actions/security-for-github-actions/security-guides/security-hardening-for-github-actions#using-third-party-actions).

This change mitigates the risk of tag retargeting to malicious code as
seen in incidents like the [tj-actions/changed-files action
compromise](https://www.stepsecurity.io/blog/harden-runner-detection-tj-actions-changed-files-action-is-compromised)
or [codfish/semantic-release-action
compromise](https://www.stepsecurity.io/blog/supply-chain-compromise-codfish-semantic-release-action)
and improves the integrity and reproducibility of the CI/CD pipeline.

## What changed?

**Action pinning:** Third-party action references in
`.github/workflows/` that used mutable tag-based references (e.g.,
`actions/checkout@v4`) have been updated to full-length commit SHAs with
a version comment (e.g., `actions/checkout@<sha> # v4`) using the
[pinact](https://github.com/suzuki-shunsuke/pinact) tool. References
that were already pinned to a SHA, or that used immutable release tags,
were left unchanged.

**Dependabot configuration:** `.github/dependabot.yml` has been updated
to ensure a `github-actions` package-ecosystem section is present with a
`cooldown` configuration (`default-days: 7`). If the file did not exist,
it was created. If a `github-actions` section already existed, only the
`cooldown` block was added or its `default-days` value was increased to
7 if it was lower. The 7-day cooldown provides a window for the
community to detect and report compromised releases before they are
automatically proposed as updates, reducing exposure to supply-chain
attacks via newly published malicious versions.

## Is this safe to merge?

Yes. The pinned SHAs correspond to the same commits that the existing
tags pointed to. No behavioral changes in action execution are
introduced. You can verify the pinned SHA value using the GitHub REST
API (e.g., the commit hash for `actions/checkout@v7` can be found in the
`sha` property in the JSON response for `GET
https://api.github.com/repos/actions/checkout/commits/v7`).

## Additional Information

For more information, please see https://aka.ms/action-pinning

---------

Co-authored-by: Eduardo Villalpando Mello <eduardovil@microsoft.com>
Co-authored-by: Rich Chiodo false <rchiodo@microsoft.com>
Copilot-Session: ee5422c8-7d8e-4ef8-a050-de857f5b799a

Author: 3 people

.github/actions/build-vsix/action.yml

@@ -22,17 +22,19 @@ runs:
   using: 'composite'
   steps:
     - name: Install Node
-      uses: actions/setup-node@v7
+      uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
       with:
         node-version: ${{ inputs.node_version }}
         cache: 'npm'
 
     - name: Rust Tool Chain setup
-      uses: dtolnay/rust-toolchain@stable
+      uses: dtolnay/rust-toolchain@7e38f4b43b4db5c8dd498af069a4f6196df1d067 # stable
+      with:
+        toolchain: stable
 
     # Jedi LS depends on dataclasses which is not in the stdlib in Python 3.7.
     - name: Use Python 3.10 for JediLSP
-      uses: actions/setup-python@v7
+      uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
       with:
         python-version: '3.10'
         cache: 'pip'

.github/actions/lint/action.yml

@@ -10,7 +10,7 @@ runs:
   using: 'composite'
   steps:
     - name: Install Node
-      uses: actions/setup-node@v7
+      uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
       with:
         node-version: ${{ inputs.node_version }}
         cache: 'npm'
@@ -36,7 +36,7 @@ runs:
       shell: bash
 
     - name: Install Python
-      uses: actions/setup-python@v7
+      uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
       with:
         python-version: '3.x'
         cache: 'pip'

.github/actions/smoke-tests/action.yml

@@ -13,13 +13,13 @@ runs:
   using: 'composite'
   steps:
     - name: Install Node
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
       with:
         node-version: ${{ inputs.node_version }}
         cache: 'npm'
 
     - name: Install Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
       with:
         python-version: '3.x'
         cache: 'pip'
@@ -43,7 +43,7 @@ runs:
 
     # Bits from the VSIX are reused by smokeTest.ts to speed things up.
     - name: Download VSIX
-      uses: actions/download-artifact@v4
+      uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
       with:
         name: ${{ inputs.artifact_name }}
 

.github/dependabot.yml

@@ -6,27 +6,35 @@ updates:
       interval: daily
     labels:
       - 'no-changelog'
+    cooldown:
+      default-days: 7
 
   - package-ecosystem: 'github-actions'
     directory: .github/actions/build-vsix
     schedule:
       interval: daily
     labels:
       - 'no-changelog'
+    cooldown:
+      default-days: 7
 
   - package-ecosystem: 'github-actions'
     directory: .github/actions/lint
     schedule:
       interval: daily
     labels:
       - 'no-changelog'
+    cooldown:
+      default-days: 7
 
   - package-ecosystem: 'github-actions'
     directory: .github/actions/smoke-test
     schedule:
       interval: daily
     labels:
       - 'no-changelog'
+    cooldown:
+      default-days: 7
 
   # Not skipping the news for some Python dependencies in case it's actually useful to communicate to users.
   - package-ecosystem: 'pip'

.github/workflows/build.yml

@@ -239,7 +239,7 @@ jobs:
           sparse-checkout-cone-mode: false
 
       - name: Install Node
-        uses: actions/setup-node@v7
+        uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: ${{ env.NODE_VERSION }}
           cache: 'npm'
@@ -273,7 +273,9 @@ jobs:
         run: python -m pip install --upgrade -r build/test-requirements.txt
 
       - name: Rust Tool Chain setup
-        uses: dtolnay/rust-toolchain@stable
+        uses: dtolnay/rust-toolchain@7e38f4b43b4db5c8dd498af069a4f6196df1d067 # stable
+        with:
+          toolchain: stable
 
       - name: Build Native Binaries
         run: nox --session native_build

.github/workflows/codeql-analysis.yml

@@ -42,7 +42,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.37.9
+        uses: github/codeql-action/init@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9
         with:
           languages: ${{ matrix.language }}
           # If you wish to specify custom queries, you can do so here or in a config file.
@@ -67,4 +67,4 @@ jobs:
       #   make release
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.37.9
+        uses: github/codeql-action/analyze@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9

.github/workflows/pr-check.yml

@@ -232,7 +232,7 @@ jobs:
           sparse-checkout-cone-mode: false
 
       - name: Install Node
-        uses: actions/setup-node@v7
+        uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: ${{ env.NODE_VERSION }}
           cache: 'npm'
@@ -266,7 +266,9 @@ jobs:
         run: python -m pip install --upgrade -r build/test-requirements.txt
 
       - name: Rust Tool Chain setup
-        uses: dtolnay/rust-toolchain@stable
+        uses: dtolnay/rust-toolchain@7e38f4b43b4db5c8dd498af069a4f6196df1d067 # stable
+        with:
+          toolchain: stable
 
       - name: Build Native Binaries
         run: nox --session native_build
@@ -507,7 +509,7 @@ jobs:
           sparse-checkout-cone-mode: false
 
       - name: Install Node
-        uses: actions/setup-node@v7
+        uses: actions/setup-node@949feb2413d6458794dcd2491c4babbbce0c15c1 # v7.1.0
         with:
           node-version: ${{ env.NODE_VERSION }}
           cache: 'npm'
@@ -548,7 +550,9 @@ jobs:
         shell: bash
 
       - name: Rust Tool Chain setup
-        uses: dtolnay/rust-toolchain@stable
+        uses: dtolnay/rust-toolchain@7e38f4b43b4db5c8dd498af069a4f6196df1d067 # stable
+        with:
+          toolchain: stable
 
       - name: Build Native Binaries
         run: nox --session native_build