Remove the LOCAL_GIT_BRANCHES setting

[ericholscher]

We introduced this here to make tests work, but it isn't how things work in production: #4984

We should remove this setting, and make our tests work properly with remote repos. I see a couple ways we could handle this:

• The make_get_branch function could manipulate the git repo so that it has a remote branch instead of a local branch
• We could mock repo.branches in the places we use it. I went down this road briefly, but it was a little bit complex.

I think the first approach is best, but I'm not sure how to do it easily.

[humitos]

I think the first approach is best, but I'm not sure how to do it easily.

We should follow the same workflow that we do in production:

1. The repository is created by another person with all its branches: we can create a temporal repository
2. We clone it from there (localhost)
3. We start running our test over the cloned one instead of the originally created

That way, I suppose that branches will be remotes and the structure of the repository will be pretty similar to what we have in production.

[stsewd]

There are some tests that use the clone step, I guess we only need to put that step in our tests