Implement new clippy lints (#5208)

* Implement new clippy lints

clippy was just updated and has a few minor issues with the code base.

* Forgotten lint hidden behind feature

common/src/static_cell.rs

@@ -46,7 +46,7 @@ mod non_threading {
             F: FnOnce() -> Result<T, E>,
         {
             self.inner
-                .with(|x| x.get_or_try_init(|| f().map(leak)).map(|&x| x))
+                .with(|x| x.get_or_try_init(|| f().map(leak)).copied())
         }
     }
 

common/src/str.rs

@@ -250,7 +250,7 @@ pub mod levenshtein {
 
     pub fn levenshtein_distance(a: &str, b: &str, max_cost: usize) -> usize {
         thread_local! {
-            static BUFFER: RefCell<[usize; MAX_STRING_SIZE]> = RefCell::new([0usize; MAX_STRING_SIZE]);
+            static BUFFER: RefCell<[usize; MAX_STRING_SIZE]> = const { RefCell::new([0usize; MAX_STRING_SIZE]) };
         }
 
         if a == b {

vm/src/builtins/memory.rs

@@ -1047,7 +1047,7 @@ impl Hashable for PyMemoryView {
                 }
                 Ok(zelf.contiguous_or_collect(|bytes| vm.state.hash_secret.hash_bytes(bytes)))
             })
-            .map(|&x| x)
+            .copied()
     }
 }
 

vm/src/stdlib/os.rs

@@ -698,7 +698,7 @@ pub(super) mod _os {
                     if self.is_symlink(vm)? {
                         do_stat(true)
                     } else {
-                        lstat().map(Clone::clone)
+                        lstat().cloned()
                     }
                 })?
             } else {