What method(s) could/should be used to repair a paper tear in the
surface of gypsum board?

This is not a cracked surface nor a hole in the surface, but is at
corner areas of the hole in the gypsum board made for mounting a
single gang electrical box. Apparently caused by careless removal of
the piece removed when making the hole. It is a surface blemish as in
only the paper covering.

I don't think this needs application of tape and spackle .