- only advance frames and request animation frames while the window is
active.
- Reset last_frame_time to None when inactive to avoid fast catch-up
after resuming focus
- This fixes an issue where if you would have a gif open and lose focus,
the app tries to speedup to catch up the elapsed time


Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Might Close #21563, I shall measure the performance, I originally only
intended the fix to fix the speed up issue as I faced it while working
on gifs.


Release Notes:

- N/A or Added/Fixed/Improved ...