fixup! Move sphinx-apidoc command to script and run in CI

.github/workflows/ci.yaml

@@ -204,7 +204,7 @@ jobs:
         run: |
           if [[ -n $(git status --porcelain) ]]; then
             git add .
-            git diff --staged
+            git diff --staged >&2
             echo "There are changes to the developer API docs. Please regenerate, commit, and push the changes." >&2
             exit 1
           fi