Remove unnecessary try / catch blocks when using the winit-based wasm-preview

Commit b2645dff6c and 4b37d9a1f1 introduced the use of spawn, which doesn't thrown anymore.

docs/astro/src/utils/slint-docs-preview.html

@@ -85,15 +85,7 @@
     async function run() {
         await slint.default();
 
-        try {
         slint.run_event_loop();
-            // this will trigger a JS exception, so this line will never be reached!
-        } catch (e) {
-            // The winit event loop, when targeting wasm, throws a JavaScript exception to break out of
-            // Rust without running any destructors. Don't rethrow the exception but swallow it, as
-            // this is no error and we truly want to resolve the promise of this function by returning
-            // the model markers.
-        }
 
         let selector = ["code.language-slint", ".rustdoc pre.language-slint", "div.highlight-slint div.highlight", "div.highlight-slint\\,no-auto-preview div.highlight"]
             .map((sel) => `${sel}:not([class*=slint\\,ignore]):not([class*=slint\\,no-preview])`).join(",");

editors/vscode/src/wasm_preview.ts

@@ -109,11 +109,7 @@ function getPreviewHtml(
 
     const vscode = acquireVsCodeApi();
     let promises = {};
-    try {
     slint_preview.run_event_loop();
-    } catch (_) {
-        // This is actually not an error:-/
-    }
 
     const canvas_id = "canvas";
 

tools/slintpad/src/lsp.ts

@@ -222,11 +222,7 @@ export class Lsp {
         style: string,
     ): Promise<Previewer> {
         if (this.#preview_connector === null) {
-            try {
             slint_preview.run_event_loop();
-            } catch (e) {
-                // this is not an error!
-            }
 
             const params = new URLSearchParams(window.location.search);
             const experimental = params.get("SLINT_EXPERIMENTAL_FEATURES");