[3.15] Run mypy with four worker processes and uv (GH-149726) (#149773)

Run mypy with four worker processes and uv (GH-149726)
(cherry picked from commit 6304eb1)

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

Author: miss-islington

.github/workflows/mypy.yml

@@ -69,12 +69,11 @@ jobs:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           persist-credentials: false
-      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+      - uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
         with:
           python-version: "3.15"
-          allow-prereleases: true
-          cache: pip
-          cache-dependency-path: Tools/requirements-dev.txt
-      - run: pip install -r Tools/requirements-dev.txt
+          activate-environment: true
+          cache-dependency-glob: Tools/requirements-dev.txt
+      - run: uv pip install -r Tools/requirements-dev.txt
       - run: python3 Misc/mypy/make_symlinks.py --symlink
-      - run: mypy --config-file ${{ matrix.target }}/mypy.ini
+      - run: mypy --num-workers 4 --config-file ${{ matrix.target }}/mypy.ini