[Feature request] Add statically compiled Linux binaries

[jroovy]

In vanilla 7-Zip, statically compiled versions are available to download as 7zzs binaries.

There are a couple usecases I can think of that would greatly benefit from static binaries:

• running 7zstd on a distro that doesn't use glibc, such as Alpine Linux
• running 7zstd on Android via Termux, where 7zstd isn't officially packaged

[sebres]

FWIW, #462 addressed something like this.