Bump actions/upload-artifact from 4 to 6 (#497)

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
...

Author: dependabot[bot]

.github/workflows/benchmark.yml

@@ -80,7 +80,7 @@ jobs:
           exit 1
 
       - name: Upload benchmark results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: bench-${{ matrix.service }}-${{ matrix.dataset }}-${{ matrix.count }}.csv
           path: bench-${{ matrix.service }}-${{ matrix.dataset }}-${{ matrix.count }}.csv