Unpin & upgrade winit to 0.30.5 (#4939)

This updates winit to 0.30.5. 

https://github.com/emilk/egui/pull/4849 Had to pin the version to
0.30.2, as a Winit patch changed the behavior of selecting a theme.
Winit 0.30.5 reverts this, so we could stick with `window.theme()`, but
the newly added `ActiveEventLoop::system_theme` is more like what egui
wants anyway, as individual windows can have theme overrides.

Also bump `smithay-clipboard` to prevent some now duplicate
dependencies.

Cargo.toml

@@ -95,9 +95,7 @@ wgpu = { version = "22.0.0", default-features = false, features = [
     # Make the renderer `Sync` even on wasm32, because it makes the code simpler:
     "fragile-send-sync-non-atomic-wasm",
 ] }
-
-# Currently can't upgrade above 0.30.2 due to https://github.com/rust-windowing/winit/issues/3837
-winit = { version = "=0.30.2", default-features = false }
+winit = { version = "0.30.5", default-features = false }
 
 [workspace.lints.rust]
 unsafe_code = "deny"