[Build] Drop gitian "version hack"

[furszy]

Built on top of #2525.

Coming from reading bitcoin#16588.

Backporting:

• build: Use git archive as source tarball  bitcoin/bitcoin#18331.
• build: Drop make dist in gitian builds bitcoin/bitcoin#18556.

[furszy]

rebased after 2525 merge.

[Fuzzbawls]

Been putting this through the gitian grinders the past days (both pre and post refactor)...and going to have to give it a NACK as it actually breaks gitian builds as-is. Further, it introduces discrepancies between CI builds and gitian builds by way of having a gitian-exclusive method of generating a source tarball, while CI builds still use make dist.

I believe that this is a prime example of a merged upstream change that was made prematurely, and without sufficient review, as Corey notates in his comments of the upstream PR post-merge. The purpose of make dist is to provide a tarball that doesn't depend on autotools whatsoever, and this breaks that by actually introducing autotools as a dependency into the source tarball build requirements...that is a glaring regression IMHO, and the upstream acceptance reads as "well, damage done...oh well", rather than correcting the issue.

[furszy]

About the first paragraph,
i run gitian twice with this and all went well. Weird that is failing there.
As a general point, a CI - gitian difference isn't really a reason for not adding a change (while the change is an improvement). The CI is for automated testing, need to cover and be adapted to whatever we do in build system. Not in the other way around.

About the second paragraph,
As far as i have seen, Corey didn't care much to push a PR reverting it in upstream. I'm fine closing it, makes sense 👍 .
I updated the genbuild area merely because of the "dirty" version topic. At the beginning wanted to be 1-1 with upstream, then started playing a bit with the relic-conf file ignore (which just saw you push a PR up for it, cool 👍), then got side-tracked with the Sapling related work that was doing and stopped working on this..

So.. all good for me here. Let's move forward, will give a try to 2541.