⬆ Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

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

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

.github/workflows/test.yml

@@ -29,7 +29,7 @@ jobs:
         run: docker compose exec -T backend bash /app/tests-start.sh "Coverage for ${{ github.sha }}"
       - run: docker compose down -v --remove-orphans
       - name: Store coverage files
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: coverage-html
           path: backend/htmlcov