[archlinux] 清理缓存包

archlinux的缓存包会占用大量的硬盘，可以用paccache命令清理：

# paccache -r

┬─[tong@T7:~]─[05:04:04 PM]
╰─>$ sudo du -sh /var/cache/pacman/pkg/
56G     /var/cache/pacman/pkg/
┬─[tong@T7:~]─[05:04:09 PM]
╰─>$ sudo paccache -r

==> finished: 7121 packages removed (disk space saved: 34.73 GiB)
┬─[tong@T7:~]─[05:06:22 PM]
╰─>$ sudo du -sh /var/cache/pacman/pkg/
21G     /var/cache/pacman/pkg/
┬─[tong@T7:~]─[05:09:29 PM]
╰─>$ 

详见：https://wiki.archlinux.org/index.php/pacman#Cleaning_the_package_cache