use alpine and link statically on linux

[malt3]

To make the perl toolchain more portable, it should be statically linked (at least for linux).
This PR adds support to build perl on alpine and (optionally) sets the link type to create a fully static perl executable.

file linux-*/perl-linux-*/bin/perl
linux-amd64/perl-linux-amd64/bin/perl: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, with debug_info, not stripped
linux-arm64/perl-linux-arm64/bin/perl: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), statically linked, with debug_info, not stripped

This also resolves #13 and helps resolve bazelbuild/rules_perl#54.

[skaji]

Duplicate of #6

According to INSTALL file in perl source code, if we compile perl statically, we won't be able to use any new extension (XS) module without recompiling perl itself.

So I won't compile perl statically for this repository.
But, of course, you can compile perl statically by yourself.

[malt3]

Do you think it may be possible to add this as a secondary release artifact? This way, users that don't require new extensions can use a static toolchain.

EDIT: would be happy to rework this PR to add the static perl toolchains as a secondary artifact (next to the dynamically linked perls).

[skaji]

I don't think perl without xs modules (such as Net::SSLeay, JSON::XS, DBI, Moose) is very useful.
So I'm not sure I want to build perl statically in this project right now.
Please feel free to build perl statically by yourself.