favicons is incorrectly listed as a peer-dependency

Overview: favicons is incorrectly listed as a peer-dependency but it is not provided by the platform. In fact, I think this may just be an error/accident and it can be removed completely: There is no indication in the PR where it was added that this was intentional, and grepping through ./src shows no imports from it. If it is intentional nonetheless, it must be moved to dependencies.

CC: ankitasen