fix: better prompt not supported message in window-setup.ts (#45017)

Update window-setup.ts

The message should simply read "is not supported" or, alternatively, "is not, and will not, be supported", but not "is and will not be supported".

lib/renderer/window-setup.ts

@@ -15,7 +15,7 @@ export const windowSetup = (isWebView: boolean, isHiddenPage: boolean) => {
 
   // But we do not support prompt().
   window.prompt = function () {
-    throw new Error('prompt() is and will not be supported.');
+    throw new Error('prompt() is not supported.');
   };
   if (contextIsolationEnabled) internalContextBridge.overrideGlobalValueFromIsolatedWorld(['prompt'], window.prompt);