clippy: fix several lint warns (#32126)

As seems #31500 still remain opened here's the next partial fix.

Fixed list: `unused_mut`, `clippy::needless_borrow`,
`clippy::match_ref_pats`, `clippy::borrow_deref_ref`, `clippy::ptr_eq`,
`clippy::unnecessary_cast`, `clippy::derivable_impls`,
`clippy::collapsible_match`, `clippy::extra_unused_lifetimes`,
`clippy::map_clone`, `clippy::manual_filter`.


- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes are part of #31500.
- [x] These changes do not require tests because are only cosmetic.

components/script/dom/node.rs

@@ -3455,7 +3455,7 @@ impl UniqueId {
             if (*ptr).is_none() {
                 *ptr = Some(Box::new(Uuid::new_v4()));
             }
-            (&*ptr).as_ref().unwrap()
+            (*ptr).as_ref().unwrap()
         }
     }
 }