perl.git moved to salsa

[Dominic Hargreaves]

I migrated perl.git to salsa: https://salsa.debian.org/perl-team/interpreter/perl
so please refer to that instead of alioth from now on.

I also migrated perl-squeeze.git which was our topgit-based repo, for
historical interest.

I haven't yet migrated the auxillary repos ansible-perl-rebuilds and
debomatic, as I'm not quite sure the best place to put those. But I think
it's just me and Niko using those so far so will coordinate directly
with him.

Cheers,
Dominic.