Bump actions/github-script from 6 to 9

Bumps [actions/github-script](https://github.com/actions/github-script) from 6 to 9.
- [Release notes](https://github.com/actions/github-script/releases)
- [Commits](https://github.com/actions/github-script/compare/v6...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>

.github/workflows/combine-prs.yml

@@ -30,7 +30,7 @@ jobs:
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
-      - uses: actions/github-script@v6
+      - uses: actions/github-script@v9
         id: create-combined-pr
         name: Create Combined PR
         with: