New review comment by Logarithmus on void-packages repository

https://github.com/void-linux/void-packages/pull/31665#discussion_r659359692

Comment:
> Yes there is, we have checksums for the tarball.

Please, read my message again. You were afraid of force pushes suddenly changing the tag contents. My little experiment proved that tag remains untouched.
**UPD** Now I've came up with this case: author deletes tag completely and then creates it again, but points it to another commit. So maybe you are right that it's better to have a hash in `template` because the package can silently break.

> Package policy is documented in the Manual; many other packages use submodules by downloading each tarball and moving to the specific place.

I don't see using `git` directly instead of tarballs being prohibited in `Manual.md`. Moreover, it documents that `do_fetch` is used to fetch sources when `distfiles` is not set. If you so strongly insist on using tarballs only, then what's the purpose of `do_fetch` then? Let's remove it altogether from `xbps-src` 

> Did you try? We use this functionality in multiple places.

Hmm... OK, looks like `https://github.com/<name>/<repo>/archive/<hash>.tar.gz` works.

> Anyhow, the issue with being "packageable" is that if writing a reasonable template is too much trouble, then it isn't packageable. It isn't that it has submodules or anything else.

There isn't any trouble in writing a template for packages with many submodules. You can just use `do_fetch` and let `git` do it's job, instead of manually copy-pasting commit hashes for each submodule every time the package updates.