Replace #[allow attributes with expect (#7796)

We do have `clippy::allow_attributes` turned on, but it doesn't seem to
work properly

crates/egui_glow/src/misc_util.rs

@@ -1,4 +1,4 @@
-#![allow(unsafe_code)]
+#![expect(unsafe_code)]
 
 use glow::HasContext as _;