chore: use std::sync::LazyLock

Removes `once_cell` as a direct dependency.

cosmic-applet-a11y/src/backend/wayland/mod.rs

@@ -12,11 +12,11 @@ use cosmic_protocols::a11y::v1::client::cosmic_a11y_manager_v1::Filter;
 use cosmic_settings_subscriptions::cosmic_a11y_manager::{
     self as thread, AccessibilityEvent, AccessibilityRequest,
 };
-use once_cell::sync::Lazy;
+use std::sync::LazyLock;
 use tokio::sync::Mutex;
 
-pub static WAYLAND_RX: Lazy<Mutex<Option<tokio::sync::mpsc::Receiver<AccessibilityEvent>>>> =
-    Lazy::new(|| Mutex::new(None));
+pub static WAYLAND_RX: LazyLock<Mutex<Option<tokio::sync::mpsc::Receiver<AccessibilityEvent>>>> =
+    LazyLock::new(|| Mutex::new(None));
 
 #[derive(Debug, Clone)]
 pub enum WaylandUpdate {