New review comment by ericonr on void-packages repository

https://github.com/void-linux/void-packages/pull/31665#discussion_r659360970

Comment:
Yes, I meant retagging as the main issue.

I guess someone has to document these policies, then. They do exist.

`do_fetch` can exist, but it's very much undesired. That a workaround exists for specific templates doesn't mean it should be used all the time.

And we prefer to use submodules explicitly rather than telling git to do things.