DEV: sidebarActive is not used anymore (#30268)

This was used in the past to show a chat sidebar when the core sidebar
was not existing.

plugins/chat/assets/javascripts/discourse/services/chat.js

@@ -35,7 +35,6 @@ export default class Chat extends Service {
 
   cook = null;
   presenceChannel = null;
-  sidebarActive = false;
   isNetworkUnreliable = false;
 
   @and("currentUser.has_chat_enabled", "siteSettings.chat_enabled") userCanChat;

plugins/chat/assets/javascripts/discourse/templates/chat.hbs

@@ -1,10 +1,5 @@
 <div id="chat-progress-bar-container"></div>
 
-{{#if this.chat.sidebarActive}}
-  <div class="full-page-chat teams-sidebar-on">
-    {{outlet}}
-  </div>
-{{else}}
 <div
   class={{concat-class
     "full-page-chat"
@@ -25,4 +20,3 @@
     {{/if}}
   </div>
 </div>
-{{/if}}