Remove tar support

[Morganamilo]

tar is slower and harder to diff. I doubt any one still uses it intentially.

There's a chance some people have not cleared their cache in two years
and still have tar based packages around. But forcing them to clear
their cache is not a big deal at all.

[Morganamilo]

I ended up removing -f but looks like we still need it for ABS packages. Even though we use git now we still delete the dir and copy it over.

[Morganamilo]

Also reading through the ABS code, do we really need to shell out to cp?

[Jguer]

Also reading through the ABS code, do we really need to shell out to cp?

A inheritance from the old inline tar.gz code, can be removed.
https://stackoverflow.com/questions/51779243/copy-a-folder-in-go

[Jguer]

#1102 now implements the changes to bash and zsh completion for this

[Jguer]

Also missing removal of case "tar" in both attribution and valid param

[Jguer]

Missing removal of config.Tarbin

[Morganamilo]

Annoyingly when searching for tar it also pulls in nextArg and target. So I couldn't really just do a find all. I was kind of relying on the CI to catch the unused for me.

[bundi78]

Hi,

sorry to be late, but for me, that feature was useful. I have to work behind an awkward proxy and --nogitclone was the only working solution to use AUR.

With 9.4.3, I have no (easy) access to AUR.

[mjruschak]

Oh boy... Any way you could add this back. Found this option useful for behind proxys. Much appreciated if we could get it back.