CI(dependabot): Bump actions/upload-artifact from 4 to 5

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 5.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/run-tox.yml

@@ -68,7 +68,7 @@ jobs:
         name: "BluePyParallel-py${{ matrix.python-version }}-${{ matrix.min_versions }}"
         token: ${{ secrets.CODECOV_TOKEN }}
     - name: Upload test artifacts
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v5
       if: always()
       with:
         name: tests-${{ matrix.python-version }}-${{ matrix.min_versions }}