Cleanups preparing for WindowContext refactor (#22475)

* Remove unnecessary WindowContext and ViewContext '_ lifetimes

* Removed some cases where WindowContext has a different name than `cx`.

Release Notes:

- N/A

crates/extensions_ui/src/extensions_ui.rs

@@ -843,7 +843,7 @@ impl ExtensionsPage {
         }
     }
 
-    fn fetch_extensions_debounced(&mut self, cx: &mut ViewContext<'_, ExtensionsPage>) {
+    fn fetch_extensions_debounced(&mut self, cx: &mut ViewContext<ExtensionsPage>) {
         self.extension_fetch_task = Some(cx.spawn(|this, mut cx| async move {
             let search = this
                 .update(&mut cx, |this, cx| this.search_query(cx))