解决办法，添加源。

sudo apt install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt update
sudo apt install php8.0 php8.0-gd php8.0-sqlite3 php8.0-curl php8.0-zip php8.0-xml php8.0-mbstring php8.0-mysql php8.0-bz2 php8.0-intl php-smbclient php8.0-imap php8.0-gmp libapache2-mod-php8.0