Add commit logging workflow

[jurrejelle]

Needs the following things setup:

1. A project board with two rows/tags/labels present: "To Port 1.20->1.21" and "To Port 1.21->1.20"
   The URL and repository of this board will be needed for 2.

2. The following secrets:

VERSION_SYNC_PROJECT_REPO: the repo that contains the board, in Owner/Repo format
VERSION_SYNC_PROJECT_BOARD_URL: https://github.com/orgs/<org>/projects/<number>
VERSION_SYNC_PROJECT_TOKEN: a raw github Private Access Token
PAT Settings:
  Resource owner: the organization

  Repository access: this repo

  Repository permissions:

  │  Permission   │     Level      │                                            Why                                            │
  │ Metadata      │ Read           │ Mandatory (auto-selected)                                                                 │
  │ Issues        │ Read and write │ gh issue create                                                                           │
  │ Pull requests │ Read           │ repos/.../commits/<sha>/pulls lookup for the Ignore Version Sync label                    │
  │ Contents      │ Read           │ reading the contents of the push/commits/PRs                                              │

  Organization permissions:

  │ Permission │     Level      │                                Why                                 │
  │ Projects   │ Read and write │ gh project view / field-list (read) + item-add / item-edit (write) │

3. when this is merged, it needs to be mirrored to 1.21

This does mean, since things will be cherry-picked back and forth, you will not be able to merge 1.20 into 1.21 anymore because otherwise commits will be there double, so you have to create a branch and cherry-pick on there for both versions.

Let me know if there's any more questions or you wanna do anything differently

[brachy84]

change this to secrets.PAT since its already used in other actions and has required perms