Bump bobg/modver from 2.8.1 to 2.9.0

Bumps [bobg/modver](https://github.com/bobg/modver) from 2.8.1 to 2.9.0.
- [Release notes](https://github.com/bobg/modver/releases)
- [Commits](bobg/modver@v2.8.1...v2.9.0)

---
updated-dependencies:
- dependency-name: bobg/modver
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/modver.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: bobg/modver@v2.8.1
+      - uses: bobg/modver@v2.9.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           pull_request_url: https://github.com/${{ github.repository }}/pull/${{ github.event.number }}