Add surcehut to forge types (graphql api)

[fgaz]

This is the proper way to add sourcehut to the forge types. Unfortunately it doesn't work, because the api can't be accessed without a token for now (and also I didn't test it), so this is only here in preparation for when the api is made public.

I will probably open another, more hacky, pr with a working implementation based on public endpoints that exist now, like the rss feeds