[fix] themes: run \#invoke after class constructor (#5757)

Move \#invoke into a microtask that will run after current call stack completes

Closes: https://github.com/searxng/searxng/issues/5756

client/simple/src/js/Plugin.ts

@@ -23,7 +23,7 @@ export abstract class Plugin {
   protected constructor(id: string) {
     this.id = id;
 
-    void this.invoke();
+    queueMicrotask(() => this.invoke());
   }
 
   private async invoke(): Promise<void> {

client/simple/src/js/plugin/MapView.ts

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
-import "ol/ol.css?inline";
+import "ol/ol.css";
 import { Feature, Map as OlMap, View } from "ol";
 import { GeoJSON } from "ol/format";
 import { Point } from "ol/geom";