version GLIBC_2.28' not found error on Ubuntu 18.04 with release binaries

[muety]

Reported by @grepthat.

When running the latest Wakapi release on Ubuntu 18.04, I'm getting this error:

./wakapi: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by ./wakapi)

Without having looked deeper into this, I'd assume that the GHA runners building the releases use a later version of glibc, which 2.27 (the default on Ubuntu 18.04) is not compatible with.

Since a lot of people are still using 18.04 (especially on servers), I think we should keep supporting it.

A potential fix would probably be to use an Ubuntu 18.04 image to build Wakapi on CI. Any thoughts, @YC?

Glibc version can be checked using:

ldd --version

Latest is 2.37.