Remove a few unnecessary usages of Lazy (#3531)

* Convert usage of Lazy to OnceLock on macOS and iOS

* Remove a few uses of Lazy that wrapped Mutex or RwLock

The `new` functions on these were made `const` in Rust 1.63.0

* Use AtomicBool instead of RwLock

src/platform_impl/linux/mod.rs

@@ -647,8 +647,7 @@ pub(crate) enum PlatformCustomCursor {
 
 /// Hooks for X11 errors.
 #[cfg(x11_platform)]
-pub(crate) static mut XLIB_ERROR_HOOKS: Lazy<Mutex<Vec<XlibErrorHook>>> =
-    Lazy::new(|| Mutex::new(Vec::new()));
+pub(crate) static mut XLIB_ERROR_HOOKS: Mutex<Vec<XlibErrorHook>> = Mutex::new(Vec::new());
 
 #[cfg(x11_platform)]
 unsafe extern "C" fn x_error_callback(