gpui_wgpu: Release surface resources during destroy (#51561)

## Summary

Implements the fix proposed by @israelrios in
https://github.com/zed-industries/zed/issues/50269#issuecomment-4049006746.

The issue comment narrowed the hang down to X11 window teardown:

- when the Settings window is closed on X11, the UI thread can stall
while `WgpuRenderer` is dropped during final `X11WindowState` teardown
- at that point, the X11 window has already been destroyed
- the proposed fix is to make `WgpuRenderer::destroy()` release
surface-bound GPU resources eagerly so the native window is destroyed
only after the `wgpu::Surface` and related resources are gone

This PR applies that change in `crates/gpui_wgpu/src/wgpu_renderer.rs`
by calling `self.resources.take()` inside `destroy()`.

## Validation

I confirmed this fix locally on Linux Mint 21.3 Cinnamon by applying it
to the `v0.227.1` build:

- opening and closing Settings no longer causes the main window to hang

## References

- Refs #50269
- Original analysis and fix proposal by @israelrios:
https://github.com/zed-industries/zed/issues/50269#issuecomment-4049006746

Release Notes:

- Fixed a Linux/X11 issue where closing the Settings window could cause
Zed to hang.

crates/gpui_wgpu/src/wgpu_renderer.rs

@@ -1620,7 +1620,9 @@ impl WgpuRenderer {
     }
 
     pub fn destroy(&mut self) {
-        // wgpu resources are automatically cleaned up when dropped
+        // Release surface-bound GPU resources eagerly so the underlying native
+        // window can be destroyed before the renderer itself is dropped.
+        self.resources.take();
     }
 
     /// Returns true if the GPU device was lost and recovery is needed.