Hide custom actions field when no applicable models selected

The entire field row is now hidden when no selected object types
have registered custom actions, avoiding an empty "Custom actions"
label.

netbox/project-static/src/forms/registeredActions.ts

@@ -40,6 +40,12 @@ export function initRegisteredActions(): void {
     if (noActionsMsg) {
       noActionsMsg.style.display = anyVisible ? 'none' : 'block';
     }
+
+    // Hide the entire field row when no actions are visible
+    const fieldRow = actionsContainer!.closest('.field-row, .mb-3');
+    if (fieldRow) {
+      (fieldRow as HTMLElement).style.display = anyVisible ? '' : 'none';
+    }
   }
 
   // Initial update