Switch Perl 5.30 to Buster?

[Tekki]

Now that buildpack-deps:stable have moved to Buster, shall we switch to Buster in Perl 5.30?

[zakame]

Based on other langs they've started having -buster and -stretch variant images as well (on top of our existing -threaded and -slim,) so if we're following suit, we'll have to adjust generate.pl a bit.

[Tekki]

At the moment Perl 5.8-18 are based on Jessie and 20-30 on Stretch. If we want Buster and Stretch variants for all versions this will probably need a little bit more than just a bit.
If we are going in this direction please close this issue.

[zakame]

Not all versions needs multi Debian dist support, only the current 5.30 and 5.28, per perlpolicy. Folks can freely adapt the Dockerfiles for older releases if they need it.

We can probably expand the debian_release option to take an array of releases aside of just a single item; I'll take a stab at this tomorrow.

Thanks @Tekki for the suggestion!