chore: Fix several style lints (#17488)

It's not comprehensive enough to start linting on `style` group, but
hey, it's a start.

Release Notes:

- N/A

crates/gpui/examples/animation.rs

@@ -9,7 +9,7 @@ impl AssetSource for Assets {
         std::fs::read(path)
             .map(Into::into)
             .map_err(Into::into)
-            .map(|result| Some(result))
+            .map(Some)
     }
 
     fn list(&self, path: &str) -> Result<Vec<SharedString>> {
@@ -23,7 +23,7 @@ impl AssetSource for Assets {
     }
 }
 
-const ARROW_CIRCLE_SVG: &'static str = concat!(
+const ARROW_CIRCLE_SVG: &str = concat!(
     env!("CARGO_MANIFEST_DIR"),
     "/examples/image/arrow_circle.svg"
 );