diagnostics: Do not run syntactic expansion on main thread (#25287)

Related to #18300

Release Notes:

- Improved diagnostic pane responsiveness with large # of diagnostics.

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Co-authored-by: Anthony Eid <hello@anthonyeid.me>
5dd351551dPiotr Osiewicz committed on 2/20/2025, 11:59:13 PM· committed by GitHubparent5ae93ce
1 file changedLine totals unavailable