Remove print_figure overrides in backend subclasses

AFAICT, `print_figure` is only called in `savefig`, and thus has no
relation to backend drawing. We went through a lot of trouble to make
`savefig` self-contained, so if this really had any effect, it would be
a bug in it instead. But other backends don't do this override and seem
to work fine, so these seem superfluous as well.

After this change, just opening a window in Qt and using the save button
did not seem to break anything, nor did running `savefig` with an
interactive window open. I did not test Wx, but given the callers of
`print_figure`, I don't see how it could be different.

Fixes matplotlib#5234

Author: QuLogic

lib/matplotlib/backends/backend_qtagg.py

@@ -71,10 +71,6 @@ def paintEvent(self, event):
         finally:
             painter.end()
 
-    def print_figure(self, *args, **kwargs):
-        super().print_figure(*args, **kwargs)
-        self.draw()
-
 
 @_BackendQT.export
 class _BackendQTAgg(_BackendQT):

lib/matplotlib/backends/backend_wx.py

@@ -614,15 +614,6 @@ def gui_repaint(self, drawDC=None):
         'xpm': 'X pixmap',
     }
 
-    def print_figure(self, filename, *args, **kwargs):
-        # docstring inherited
-        super().print_figure(filename, *args, **kwargs)
-        # Restore the current view; this is needed because the artist contains
-        # methods rely on particular attributes of the rendered figure for
-        # determining things like bounding boxes.
-        if self._isDrawn:
-            self.draw()
-
     def _on_paint(self, event):
         """Called when wxPaintEvt is generated."""
         _log.debug("%s - _on_paint()", type(self))