fixed service name to get container id

Author: Hardcode3

.github/workflows/dynamic_tests.yaml

@@ -52,8 +52,8 @@ jobs:
       - name: Copy coverage report from container
         run: |
           mkdir -p coverage_report
-          docker cp $(docker-compose ps -q fastapi_expense_backend):/app/htmlcov ./coverage_report
-          
+          docker cp $(docker-compose ps -q backend):/app/htmlcov ./coverage_report
+
       - name: Upload coverage report
         uses: actions/upload-artifact@v4
         with: