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

@@ -76,7 +76,7 @@ jobs:
           COV_CORE_SOURCE: .
           COV_CORE_CONFIG: .coveragerc
           COV_CORE_DATAFILE: .coverage.eager
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}