Instantly acknowledge workspace/diagnostic/refresh (#61772)

Closes https://github.com/zed-industries/zed/issues/61692

Makes no sense to wait for anything at all when receiving such requests,
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#diagnostic_refresh
does not imply anything either.

Release Notes:

- Fixed diagnostics refresh deadlocking certain language servers
1efdc3e63eKirill Bulatov committed on 7/28/2026, 12:32:28 PM· committed by GitHubparenta8b57a2
2 files changedLine totals unavailable