Allow relative assets in rust > 1.88 (#4658)

* Allow relative assets in rust > 1.88 and assets outside of the crate in
binary crates

* undo changes to assets outside of the crate

* don't use relative assets in examples

examples/wgpu-texture/src/main.rs

@@ -11,7 +11,7 @@ use winit::window::WindowAttributes;
 mod demo_renderer;
 
 // CSS Styles
-static STYLES: Asset = asset!("./src/styles.css");
+static STYLES: Asset = asset!("/src/styles.css");
 
 // WGPU settings required by this example
 const FEATURES: Features = Features::PUSH_CONSTANTS;