Notify pull request authors about merge conflicts (#732)

This patch adds a GitHub Actions workflow to automatically notify pull
request authors about merge conflicts by commenting at and labeling the
pull request.

.github/workflows/check-merge-conflict.yml

@@ -0,0 +1,21 @@
+name: Merge conflict check
+on:
+ push:
+ pull_request_target:
+ types:
+ - opened
+ - synchronize
+
+jobs:
+ main:
+ runs-on: ubuntu-latest
+ steps:
+ - name: Check for dirty pull requests
+ uses: eps1lon/actions-label-merge-conflict@releases/2.x
+ with:
+ dirtyLabel: "status:conflicts"
+ repoToken: "${{ secrets.GITHUB_TOKEN }}"
+ commentOnDirty: |
+ This pull request has conflicts ☹
+ Please resolve those so we can review the pull request.
+ Thanks.