lsp: Do not pass in null diagnostic identifiers (#53272)

This fixes a crash with new Preview versions of tsgo after
https://github.com/microsoft/typescript-go/pull/3313

Self-Review Checklist:

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

Closes #ISSUE

Release Notes:

- N/A
bc4d25ca76Piotr Osiewicz committed on 4/6/2026, 9:38:51 PM· committed by GitHubparentfb2bff8
2 files changedLine totals unavailable