Elide lifetimes where possible after rustup (#34824)

The new version of rust allows us to elide some lifetimes and clippy is
now complaining about this. This change elides them where possible and
removes the clippy exceptions.

Fixes #34804.

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

components/script/script_thread.rs

@@ -463,7 +463,7 @@ impl<'a> ScriptMemoryFailsafe<'a> {
     }
 }
 
-impl<'a> Drop for ScriptMemoryFailsafe<'a> {
+impl Drop for ScriptMemoryFailsafe<'_> {
     #[allow(crown::unrooted_must_root)]
     fn drop(&mut self) {
         if let Some(owner) = self.owner {