Update github actions fprettify workflow to output a warning rather than

an error

.github/workflows/check_policies.yml

@@ -19,6 +19,6 @@ jobs:
       - uses: actions/checkout@v3
       - run: pip install fprettify
       - run: fprettify --config .fprettify.ini --diff --recursive src
-      - run: test -z "$($FPRETTIFY_COMMAND)"
+      - run: if [ ! -z $($FPRETTIFY_COMMAND) ]; then echo "::warning::Code formatting issues detected"; fi
         env:
           FPRETTIFY_COMMAND: fprettify --config .fprettify.ini --diff --recursive src