fix: Small fixes before release, b=(closes #7940), c=tabs, workspaces

src/zen/tabs/zen-tabs/vertical-tabs.css

@@ -757,6 +757,7 @@
   /* Center items in essentials container */
   & .zen-essentials-container {
     justify-content: center;
+    grid-template-columns: 1fr !important;
   }
 
   /* Style new tab button when collapsed */

src/zen/workspaces/ZenWorkspaces.mjs

@@ -929,7 +929,7 @@ var ZenWorkspaces = new (class extends ZenMultiWindowFeature {
 
     const onWorkspaceIconContainerClick = this.onWorkspaceIconContainerClick.bind(this);
     for (const element of document.querySelectorAll('.PanelUI-zen-workspaces-icons-container')) {
-      element.addEventListener('command', onWorkspaceIconContainerClick);
+      element.addEventListener('click', onWorkspaceIconContainerClick);
     }
 
     document