feat(tp): add rate limiting checks

[solnic]

This addresses suggestions from #987 (review) specifically:

You could already drop rate-limited items before adding them to the buffer. And you could drop rate-limited items in the scheduler before you pass them down to the transport

---

#skip-changelog

[github-actions]

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Generated by 🚫 dangerJS against 6c14e1c

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}