Ensure inlay hint toggling with modifiers happens fast (#25852)

Follow-up of https://github.com/zed-industries/zed/pull/25766 
Fixes the bugs found:

* modifier toggle not happening instantly due to `edit_debounce_ms`
considered
* hint update race that ignored the cache clear

Release Notes:

- N/A
42571e405fKirill Bulatov committed on 3/1/2025, 8:15:57 AM· committed by GitHubparent2d61a51
2 files changedLine totals unavailable