fix: remove unused Plus import from lucide-react

- Removed unused Plus import that was added but never used
- Cleanup after PR review

Author: Tajudeen

src/vs/workbench/contrib/cortexide/browser/react/src/sidebar-tsx/SidebarChat.tsx

@@ -86,7 +86,6 @@ import {
 	Text,
 	Image as ImageIcon,
 	FileText,
-	Plus,
 } from "lucide-react";
 import {
 	ChatMessage,