ci: Add conventional commits check (#3884)

## PR Checklist

Please check if your PR fulfills the following requirements:

- [x] Tests for the changes have been added (for bug fixes / features)
- [x] Docs have been added / updated (for bug fixes / features)


## PR Type

Fixing part of
https://github.com/alexeagle/rules-doctor/actions/runs/20065968971/job/57554491288#step:6:1

<!-- Please check the one that applies to this PR using "x". -->

- [ ] Bugfix
- [ ] Feature (please, look at the "Scope of the project" section in the
README.md file)
- [ ] Code style update (formatting, local variables)
- [ ] Refactoring (no functional changes, no api changes)
- [ ] Build related changes
- [X] CI related changes
- [ ] Documentation content changes
- [ ] Other... Please describe:


## What is the current behavior?
<!-- Please describe the current behavior that you are modifying, or
link to a relevant issue. -->

Issue Number: N/A


## What is the new behavior?


## Does this PR introduce a breaking change?

- [X] Yes
- [] No


<!-- If this PR contains a breaking change, please describe the impact
and migration path for existing applications below. -->

Might possibly make other PRs unmergeable when it's merged.

## Other information

---------

Co-authored-by: Chris Bachhuber <[email protected]>

Author: cbachhuber

.github/workflows/conventional-commits.yaml

@@ -0,0 +1,16 @@
+name: Verify PR title/description
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+permissions:
+  pull-requests: read
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: amannn/action-semantic-pull-request@v6
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}