Automatic snapshots for `-Syu` too

[xfzv]

With the following in ~/.config/aura/config.toml:

[backups]
automatic = true

aura will automatically create a package set snapshot when running aura -Au. This feature is really convenient.

Any chance we could also enable automatic snapshots in the config file for Pacman updates when running aura -Syu?

[fosskers]

Yes actually, since I entirely control the capturing of arguments to the underlying pacman.

One critical difference between -Su and -Au would be that with -Au, I wait until after the user has accepted the upgrade before I save the package state. With -Su I'd have no way of doing that, since by that point control has already been relinquished to pacman. If that sounds reasonable, I could implement this.