Bump actions/download-artifact from 2.1.0 to 4.1.7 in /.github/workflows

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 2.1.0 to 4.1.7.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v2.1.0...v4.1.7)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
...

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

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -179,7 +179,7 @@ jobs:
           echo "Failed to restore Python venv from cache"
           exit 1
       - name: Download all coverage artifacts
-        uses: actions/download-artifact@v2.1.0
+        uses: actions/download-artifact@v4.1.7
       - name: Combine coverage results
         run: |
           . venv/bin/activate