clippy: Fix warning in fonts/platform/macos/font_list.rs (#33971)

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

components/fonts/platform/macos/font_list.rs

@@ -52,7 +52,7 @@ impl LocalFontIdentifier {
         // listed in the font.
         let file = File::open(Path::new(&*self.path)).ok()?;
         let mmap = unsafe { Mmap::map(&file).ok()? };
-        Some((&mmap[..]).to_vec())
+        Some(mmap[..].to_vec())
     }
 }