Could be a good idea too put not only the git mirror, but bundles as well.
Otherwise, we've got problems in GHA like:
--2024-01-23 22:56:03-- (try:20) https://gmplib.org/download/gmp/gmp-6.3.0.tar.xz
Connecting to gmplib.org (gmplib.org)|130.242.124.102|:443... failed: Connection timed out.
Giving up.