Remove now unnecessary bindings of signal callbacks in the public API.
There might be some false positives that need rebinding if they were
meant to be public.
No regular expressions were harmed in the making of this commit.
(Nah, just kidding.)
Happy new year to the wonderful Godot community!
We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.
Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
