Update ci.yml

Author: jenschude

.github/workflows/ci.yml

@@ -137,7 +137,7 @@ jobs:
         run: ./gradlew codeCoverageReport
 
       - name: Send code coverage report to Codecov.io
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@5ecb98a3c6b747ed38dc09f787459979aebb39be # v4.3.1
         with:
             token: ${{ secrets.CODECOV_TOKEN }}
   docs: