系统升级
sudo apt update && sudo apt dist-upgrade && sudo apt autoremove
sudo apt-get install update-manager-core
sudo RELEASE_UPGRADER_ALLOW_THIRD_PARTY=1 do-release-upgrade # 操作前，可能需要重启
Checking for a new Ubuntu release
You have not rebooted after updating a package which requires a reboot. Please reboot before upgrading.
其他版本
默认只装 LTS 版本
/etc/update-manager/release-upgrades
Prompt=lts