Update to Rust 1.65 (#2314)

* Update to Rust 1.65

Because then you can use dynamic linking on Linux

* Fix a bunch of clippy lints

* Update changelogs

* More clippy fixes

crates/egui_demo_app/src/lib.rs

@@ -59,15 +59,13 @@ pub fn init_wasm_hooks() {
 #[wasm_bindgen]
 pub async fn start_separate(canvas_id: &str) -> Result<WebHandle, wasm_bindgen::JsValue> {
     let web_options = eframe::WebOptions::default();
-    let handle = eframe::start_web(
+    eframe::start_web(
         canvas_id,
         web_options,
         Box::new(|cc| Box::new(WrapApp::new(cc))),
     )
     .await
-    .map(|handle| WebHandle { handle });
-
-    handle
+    .map(|handle| WebHandle { handle })
 }
 
 /// This is the entry-point for all the web-assembly.