Bump actions/github-script from 8 to 9

Bumps [actions/github-script](https://github.com/actions/github-script) from 8 to 9.
- [Release notes](https://github.com/actions/github-script/releases)
- [Commits](actions/github-script@v8...v9)

---
updated-dependencies:
- dependency-name: actions/github-script
  dependency-version: '9'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/upstream-monitor.yml

@@ -35,7 +35,7 @@ jobs:
 
       - name: Open an issue for manual review
         if: steps.upstream.outputs.update == 'true'
-        uses: actions/github-script@v8
+        uses: actions/github-script@v9
         with:
           script: |
             const fs = require('fs');