CI: update version string

Author: tacaswell

.github/workflows/testing.yml

@@ -44,4 +44,4 @@ jobs:
         coverage report
 
     - name: Upload code coverage
-      uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v1
+      uses: codecov/codecov-action@18283e04ce6e62d37312384ff67231eb8fd56d24 # v5.4.3