Replace remaining uses of sync.py

.github/workflows/rebuild.yml

@@ -87,10 +87,7 @@ jobs:
 
       - name: Generate workflows
         working-directory: pr-checks
-        run: |
-          python -m pip install --upgrade pip
-          pip install ruamel.yaml==0.17.31
-          python3 sync.py
+        run: ./sync.sh
 
       - name: "Merge in progress: Finish merge and push"
         if: steps.merge.outputs.merge-in-progress == 'true'

.github/workflows/script/verify-pr-checks.sh

@@ -19,7 +19,7 @@ if [ ! -z "$(git status --porcelain)" ]; then
     # If we get a fail here then the PR needs attention
     git diff
     git status
-    >&2 echo "Failed: PR checks are not up to date. Run 'cd pr-checks && python3 sync.py' to update"
+    >&2 echo "Failed: PR checks are not up to date. Run 'cd pr-checks && ./sync.sh' to update"
 
     echo "### Generated workflows diff" >> $GITHUB_STEP_SUMMARY
     echo "" >> $GITHUB_STEP_SUMMARY