Command to only clear caches from yay (leave pacman parts untouched)

[t-nil]

Is your feature request related to a problem? Please describe.

I'm always frustrated when I enter yay -Sc --noconfirm to clean up substantial amounts of space (primarily build artifacts and packages in .cache/yay), but yay also removes older versions of installed packages from my pacman cache.

I understand that pacmans behaviour is the same when using -Sc, but that's why I use paccache. Having older versions of packages has quite literally saved my day multiple times.

Describe the solution you'd like

yay -Sc --aur (or similar) doing only the last two steps of cleaning (remove all other AUR packages from cache / remove ALL untracked AUR files). Sadly yay -Yc is already taken

Ideally also a corresponding option, to be remembered in config.json.

Describe alternatives you've considered

Running echo -ne n\ny\ny\ny | yay -Sc

Although it is doable, it makes the clean command a lot less ergonomic (which it clearly is meant to be, since it tries to one-command clean all relevant parts of both package managers). Also, losing a lot of old package versions by accident is no joke IMHO.

Additionally, I personally find the info "Packages to keep: All locally installed packages" misleading, because to me that's to close to "delete only versions of not installed packages", while it actually (apparently) means "delete every version of a package thats not the installed one). So maybe additionally add CAVEATs to manpage and command output?

Additional context

#354 is not about the same problem but mentions the behaviour