The signatures couldn't be verified because no keyring is specified

# apt-get update
Get:1 http://mirrors.ustc.edu.cn/kali kali-rolling InRelease [41.5 kB]
Err:1 http://mirrors.ustc.edu.cn/kali kali-rolling InRelease
  The signatures couldn't be verified because no keyring is specified
Reading package lists... Done
W: GPG error: http://mirrors.ustc.edu.cn/kali kali-rolling InRelease: The signatures couldn't be verified because no keyring is specified
E: The repository 'http://http.kali.org/kali kali-rolling InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled 

/etc/apt/source.list
deb http://http.kali.org/kali kali-rolling main contrib non-free non-free-firmware

wget https://http.kali.org/kali/pool/main/k/kali-archive-keyring/kali-archive-keyring-udeb_2025.1_all.udeb
sudo dpkg -i kali-archive-keyring-udeb_2025.1_all.udeb
sudo apt update