Add api-changes.yml workflow to replace danger-pr (#55341)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/55341

Changelog:
[INTERNAL] [CHANGED] - Add api-changes.yml workflow to replace danger-pr for detecting changes in the js api

  The workflow:
  - Triggers on `pull_request_target` for opened, edited, reopened, and synchronize events
  - Checks out the main branch (for security, using trusted code)
  - Runs the `diff-js-api-changes` action to detect API changes
  - Posts a PR comment using the generic `post-pr-comment` action

  The PR comment script creates, updates, or deletes a bot comment based on whether
  there are any sections to report, using a marker to identify existing bot comments.

Reviewed By: huntie

Differential Revision: D90991845

fbshipit-source-id: 753475a7c24df8bc581b2ab47bfad1f5551c823c