fix: run Prettier in CI (openai#4681)

This was supposed to be in openai#4645.

Author: bolinfest

.github/workflows/ci.yml

@@ -60,3 +60,6 @@ jobs:
         run: ./scripts/asciicheck.py codex-cli/README.md
       - name: Check codex-cli/README ToC
         run: python3 scripts/readme_toc.py codex-cli/README.md
+
+      - name: Prettier (run `pnpm run format:fix` to fix)
+        run: pnpm run format