LSP: strike-through UI for `Deprecated` DiagnosticTag

[hokein]

Check for existing issues

• [X] Completed

Describe the feature

Per the LSP spec, if a diagnostic is with a Deprecated tag, editors are allowed to rendered diagnostics with this tag strike through.

Below (with clangd) is the VSCode:

Zed:

If applicable, add mockups / screenshots to help present your vision of the feature

No response