chore: Update ZenUIManager and Zen browser theme

src/browser/base/content/ZenUIManager.mjs

@@ -73,9 +73,5 @@ var gZenVerticalTabsManager = {
   toggleExpand() {
     let expanded = !this.expanded;
     Services.prefs.setBoolPref('zen.view.sidebar-expanded', expanded);
-
-    let toolbox = document.getElementById('navigator-toolbox');
-    toolbox.removeAttribute('width');
-    toolbox.style.removeProperty('width');
   },
 };

src/browser/themes/shared/zen-browser-shared.css

@@ -401,8 +401,9 @@ toolbarbutton#scrollbutton-up {
   top: 50%;
 }
 
-.tabbrowser-tab:hover .tab-close-button {
-  display: none; /* TODO: fix this? or maybe not? */
+.tabbrowser-tab[open="true"]:hover .tab-close-button {
+  /* TODO: fix this */
+  /*display: block;*/
 }
 
 .tab-content {