Fix double quoted strings in workflow

.github/workflows/push-checks.yml

@@ -37,7 +37,7 @@ jobs:
       env:
         ROOT_SHA: ${{github.base_ref}}
       run: |
-        DATA=$(jq .before $GITHUB_EVENT_PATH)
+        DATA=$(jq --raw-output .before $GITHUB_EVENT_PATH)
 
         # stop the build if there are Python syntax errors or undefined names, ignore existing 
         git diff "$DATA" | flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics --diff