Bump actions/upload-artifact from 2 to 3

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 2 to 3.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v2...v3)

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

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

.github/workflows/test.yml

@@ -38,7 +38,7 @@ jobs:
 
         - name: Upload results
           if: always()
-          uses: actions/upload-artifact@v2
+          uses: actions/upload-artifact@v3
           with:
             name: Unit test coverage (Python ${{ matrix.python-version }})
             path: "*.xml"