add libz to cpython build

[Gentle]

No description provided.

[Gentle]

libxz requires automake autoconf po4a and libtool, I did not check yet if those exist on CI

also zstd in particular is quite big, do we want all compression libraries?

[dicej]

also zstd in particular is quite big, do we want all compression libraries?

libz is the most-requested one, so we should include that by default, at least. Perhaps we could exclude the other ones by default and allow the developer to optionally enable them somehow? I suspect the only way to do that would be to e.g. check an environment variable in build.rs (e.g. COMPONENTIZE_PY_ENABLE_ZSTD), which means anyone who wants zstd needs to build a custom version of componentize-py, which is awkward; not sure if there's a better way.

[Gentle]

I think you can use feature flags in build.rs but that still would mean separate componentize-py versions

technically we could build cpython multiple times, making componentize-py bigger, and then adding an option for minimal, zlib-only or full runtimes

[Gentle]

we agreed on Zulip to only include zlib for now

[dicej]

Thanks!