mlua breaks on musl builds with rust 1.93

[bvgastel]

I'm getting link errors if targeting 1.93, with 1.92 it works. Rust 1.93 switched to a newer musl version (from 1.2.3 to 1.2.5), that handles fopen64 vs fopen different.

Example link error (same for freopen64, mkstemp64, etc):

error: undefined symbol: fopen64

It can be fixed by defining _LARGEFILE64_SOURCE or _GNU_SOURCE when compiling the Lua source, on musl targets.