Consider whether utils.depend.dep_dot is needed

[OndrejMarsalek]

It was a no-op until recently, with no apparent ill effects.

[OndrejMarsalek]

@ceriottm, what do you think?

[ceriottm]

So the idea was that when doing something like a matrix-vector dot operation, the result should not carry the depend machinery attached to the factors. I think that even if we do not use this feature now, it is a sane thing to have to avoid possible headaches in the future.