Remove unused useRouter import from ProfileDropdown.

main-website/components/ProfileDropdown.tsx

@@ -1,12 +1,10 @@
 'use client'
 
 import { useEffect, useState } from 'react'
-import { useRouter } from 'next/navigation'
 
 export default function ProfileDropdown() {
     const [open, setOpen] = useState(false)
     const [profile, setProfile] = useState<{ user?: string; email?: string }>({})
-    const router = useRouter()
 
     useEffect(() => {
         fetch('/api/me')