docker: Install archlinux-keyring from source

[obbardc]

The arch linux tests require a newer version of archlinux-keyring than what is in Debian stable; so revert back to pulling the latest version.

This partially reverts 36cf333.

[evelikov]

Should probably add a scarier inline message, otherwise the next person will remove the code.

[obbardc]

Should probably add a scarier inline message, otherwise the next person will remove the code.

Do you have a suggestion?

# WARNING: removing this will most likely break archlinux support is not good enough ?

[evelikov]

# Pull the latest archlinux-keyring, since the one in Debian is bound
# to get outdated sooner or later.
# WARNING: removing this will most likely break archlinux support

How about something like this in both places?

Edit: A reference to a closed/fixed issue is misleading at best.

[obbardc]

@evelikov Can we pull the master branch of the keyring ? Seems like the tag you originally used is outdated (before the version in Debian, which is most lilkely why it was replaced with the keyring pacakge in Debian).

[evelikov]

Nice one - completely forgot we're using a tag. Switching to master or fishing out automatically picking* the newest tag, would be better.

[obbardc]

@evelikov How does this look now then?