Update actions/upload-artifact action to v4

Author: renovate[bot]

.github/workflows/verify.yml

@@ -240,7 +240,7 @@ jobs:
           . venv/bin/activate
           pytest --log-level info tests/*.py --cov='.'
       - name: Upload coverage artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: coverage-${{ matrix.python-version }}
           path: .coverage