CI: Bump actions/upload-artifact from 5.0.0 to 6.0.0

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@330a01c...b7c566a)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/extension-validation.yml

@@ -103,7 +103,7 @@ jobs:
 
       - name: Upload validation reports
         if: always()
-        uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         with:
           name: validation-reports
           path: |