https://nvd.nist.gov/vuln/detail/CVE-2024-3094

Building of the glib introspection modules has been moved from
gobject-introspection to glib and of course that requires
gobject-introspection but gobject-introspection still depends
on glib forcing a double-build of glib.

Fixes #84

Fixes #85

Pipenv update fixes the "Running interpreter doesn't sufficiently support
code object introspection" warning.

Disabling introspection and tests.

The build of gettext on Sonoma (at least arm64) ends with:

ld: Undefined symbols:
  _iconv_ostream_create, referenced from:
      <initial-undefines>
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I tried updating gettext to the latest version (which fixes some Sonoma problems
so it is good to do in any case) but this doesn't resolve the problem.

Building libiconv and adding it as a dependency of gettext seems to fix
the issue. I based the autogen args on what is currently used in the corresponding
Homebrew formula.

Autotools build isn't supported any more so let's use meson.
Except "unstable" modules, which use the latest git version that supports
Apple processors, a64-neon should be disabled for the 0.42.2 where the support
hasn't been added yet.

For clarity & consistency with the other modulesets.

This is already what modulesets-unstable builds.