ci(tests): codecov/codecov-action@v4

See also:
- https://github.com/codecov/codecov-action/releases/tag/v4.0.0
- https://github.com/codecov/codecov-action/releases/tag/v4.0.1

Author: tony

.github/workflows/tests.yml

@@ -46,7 +46,7 @@ jobs:
           COV_CORE_CONFIG: pyproject.toml
           COV_CORE_DATAFILE: .coverage.eager
 
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}