Bump actions/upload-artifact from 4 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -79,7 +79,7 @@ jobs:
           ./scripts/test-examples.py -v -k --path=./build/examples
 
       - name: Upload JUnit Tests
-        uses: actions/upload-artifact@v4  # upload test results
+        uses: actions/upload-artifact@v6  # upload test results
         if: success() || failure()        # run this step even if previous step failed
         with:
           name: test-results