Github action to require towncrier changelogs before merging a PR

changelog-check.yml

name: changelog-check
on:
  - pull_request
jobs:
  changelog:
    runs-on: ubuntu-latest
    steps:
      - name: Get base depth
        id: base-depth
        run: echo "base-depth=$(expr ${{ github.event.pull_request.commits }} + 1)" >> $GITHUB_OUTPUT

      - uses: actions/checkout@v4
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: ${{ steps.base-depth.outputs.base-depth }}
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - name: Install dependencies
        run: |
          python -m pip install -e .
          python -m pip install towncrier
      - name: Check for new changelogs
        run: |
          git fetch --no-tags origin +refs/heads/main:refs/remotes/origin/main
          towncrier check --compare-with origin/main