ui_macros: Remove `DerivePathStr` macro (#30862)

This PR removes the `DerivePathStr` macro, as it is no longer used.

Also removes the `PathStaticStr` macro from `gpui_macros`, which was
also unused.

Release Notes:

- N/A
03419da6f1Marshall Bowers committed on 5/17/2025, 10:05:55 AM· committed by GitHubparentf56960a
9 files changedLine totals unavailable