CI: (deps): 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/assign-milestone.yml

@@ -15,7 +15,7 @@ jobs:
     name: Assign Latest Milestone
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/github-script@v8
+      - uses: actions/github-script@v9
         name: Run script
         with:
           script: |

.github/workflows/nightly-builds.yml

@@ -44,7 +44,7 @@ jobs:
           touch tests-nightly.log build.log linkchecker.log
 
       - name: Report failures
-        uses: actions/github-script@v8
+        uses: actions/github-script@v9
         with:
           script: |
             const fs = require('fs');