Fix Pro package tests: run yarn workspace from repo root

The yarn workspace command must run from the workspace root, not from
a subdirectory. Added working-directory: . to the test run step.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

.github/workflows/pro-test-package-and-gem.yml

@@ -241,6 +241,7 @@ jobs:
           yarn install --frozen-lockfile --no-progress --no-emoji
 
       - name: Run JS unit tests for Pro package
+        working-directory: .
         run: yarn workspace react-on-rails-pro-node-renderer run ci
         env:
           JEST_JUNIT_OUTPUT_DIR: ./jest