There is an updated pull request by tornaria against master on the void-packages repository

https://github.com/tornaria/void-packages xbps-mirror
https://github.com/void-linux/void-packages/pull/34398

etc/conf: implement XBPS_MIRROR for remote repos
Setting this variable will make xbps-src use an alternative mirror for remote repositories.

Using this variable one can change the remote repository for all architectures in a single setting and without the need to modify `etc/xbps.d/repos-remote*.conf`. This is much more convenient as it allows changing remote repos without a dirty worktree.

To use just add a line like the following to `etc/conf`:

    XBPS_MIRROR=https://repo-us.voidlinux.org/

We also disable `00-repository-main.conf` for cross so we don't use the remote repo from the xbps package.

#### Testing the changes
- I tested the changes in this PR: **YES**

A patch file from https://github.com/void-linux/void-packages/pull/34398.patch is attached