Use geo.mirror.pkgbuild.com as the default mirror
geo.mirror.pkgbuild.com is a GeoDNS mirror that points to the sponsored mirrors.
This avoids the usage of Arch's own infrastructure (mirror.pkgbuild.com) for large downloads. See infrastructure!522 (merged) for details.
Similar change was made in ci-scripts!4 (merged).
Edited by nl6720