Bump actions/upload-artifact from 5 to 6 (#568)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v5...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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/verify.yaml

@@ -89,7 +89,7 @@ jobs:
           echo "ARTIFACT_NAME=coverage_${{ runner.os }}-py-${{ matrix.python-version }}" | sed 's|\\.\\*||g' >> "$GITHUB_ENV"
           poetry run pytest -n auto --cov-context test --cov --cov-report=xml tests
       - name: Upload coverage artifact
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           include-hidden-files: true
           if-no-files-found: error
@@ -148,7 +148,7 @@ jobs:
           poetry run diff-quality --violations flake8 --include-untracked
           poetry run diff-quality --violations pylint --include-untracked
       - name: Upload single coverage artifact
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           include-hidden-files: true
           if-no-files-found: error