MNT: Remove return_all kwarg from gridspec get_position

This follows the deprecation period.

Author: greglucas

doc/api/next_api_changes/removals/23XXX-GL.rst

@@ -9,3 +9,5 @@ or GUI-specific methods if embedding.
 
 There is no replacement, it was considered an internal helper.
 
+The **return_all** keyword argument has been removed from ``gridspec.get_position()``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

lib/matplotlib/gridspec.py

@@ -664,8 +664,7 @@ def is_first_col(self):
     def is_last_col(self):
         return self.colspan.stop == self.get_gridspec().ncols
 
-    @_api.delete_parameter("3.4", "return_all")
-    def get_position(self, figure, return_all=False):
+    def get_position(self, figure):
         """
         Update the subplot position from ``figure.subplotpars``.
         """
@@ -679,12 +678,7 @@ def get_position(self, figure, return_all=False):
         fig_top = fig_tops[rows].max()
         fig_left = fig_lefts[cols].min()
         fig_right = fig_rights[cols].max()
-        figbox = Bbox.from_extents(fig_left, fig_bottom, fig_right, fig_top)
-
-        if return_all:
-            return figbox, rows[0], cols[0], nrows, ncols
-        else:
-            return figbox
+        return Bbox.from_extents(fig_left, fig_bottom, fig_right, fig_top)
 
     def get_topmost_subplotspec(self):
         """