Move servers back from the background thread (#44696)

Partial revert of https://github.com/zed-industries/zed/pull/44631

With this and `sccache` enabled, I get 
<img width="3456" height="1096" alt="image"
src="https://github.com/user-attachments/assets/937760fb-8b53-49f8-ae63-4df1d31b292b"
/>

and r-a infinitely hangs waiting on this.

Release Notes:

- N/A
1afe29422bKirill Bulatov committed on 12/12/2025, 11:16:17 AM· committed by GitHubparenta8aa762
4 files changedLine totals unavailable