Fixes #22529: Ensure navigation menu is navigable via keyboard (#22540)

netbox/project-static/styles/transitional/_navigation.scss

@@ -1,5 +1,13 @@
 // Navbar and light theme styling
 .navbar-vertical.navbar-expand-lg {
+  // Render the <button> menu headings identically to the surrounding nav links
+  .navbar-collapse .nav-item.dropdown > button.nav-link {
+    width: 100%;
+    background-color: transparent;
+    border: 0;
+    text-align: left;
+  }
+
   // Adjust hover color & style for menu items
   .navbar-collapse {
     .nav-link-icon,

netbox/utilities/templates/navigation/menu.html

@@ -22,14 +22,14 @@
     <li class="nav-item dropdown">
 
       {# Menu heading #}
-      <a class="nav-link dropdown-toggle" href="#" data-bs-toggle="dropdown" data-bs-auto-close="false" role="button" aria-expanded="false" aria-label="{{ menu.label }}">
+      <button type="button" class="nav-link dropdown-toggle" data-bs-toggle="dropdown" data-bs-auto-close="false" aria-expanded="false" aria-label="{{ menu.label }}">
         <span class="nav-link-icon d-md-none d-lg-inline-block">
           <i class="{{ menu.icon_class }}" aria-hidden="true"></i>
         </span>
         <span class="nav-link-title">
           {{ menu.label }}
         </span>
-      </a>
+      </button>
 
       {# Menu groups #}
       <div class="dropdown-menu">