Viacheslav Ostroukh authored Jun 14, 2021 and Viacheslav Ostroukh committed Jun 18, 2021

`renderer` argument of mplot3d's `do_3d_projection()` is deprecated in
Matplotlib 3.4. This commit switches from using (also deprecated) `renderer.M`
to `self.axes.M`.

A warning about `renderer` being deprecated is still emitted, but we still
need to keep `renderer=None` statements for reverse compatibility.