Fix loading of a simple ckeditor

The mention plugin is required by the emoji plugin.

Author: BurntimeX

ts/WoltLabSuite/Core/Component/Ckeditor/Configuration.ts

@@ -215,7 +215,7 @@ class ConfigurationBuilder {
 
   #setupMention(): void {
     if (!this.#features.mention) {
-      this.#removePlugins.push("Mention", "WoltlabMention");
+      this.#removePlugins.push("WoltlabMention");
     }
   }