docs(build-options): remove enableProdMode() reference

It's discouraged now: https://angular.dev/api/core/enableProdMode

"Using this method is discouraged as the Angular CLI will set production mode when using the optimization option."

docs/angular/build-options.md

@@ -49,10 +49,6 @@ import { routes } from './app/app.routes';
 import { AppComponent } from './app/app.component';
 import { environment } from './environments/environment';
 
-if (environment.production) {
-  enableProdMode();
-}
-
 bootstrapApplication(AppComponent, {
   providers: [
     { provide: RouteReuseStrategy, useClass: IonicRouteStrategy },