Deprecate redundant axes parameter to RadialLocator.

We can just directly fetch the relevant information from
`locator.axis.axes`; the case where `locator.axis.axes` was different
from `axes` was not tested and doesn't make much sense anyways.

The change also goes in the direction of having Locators carry less
state (and hopefully, in the future, not being associated with an axis,
but rather having the axis passed as argument to `__call__`).

Author: anntzer

doc/api/next_api_changes/deprecations/30469-AL.rst

@@ -0,0 +1,4 @@
+The *axes* parameter of ``RadialLocator``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+... is deprecated. `~.polar.RadialLocator` now fetches the relevant information
+from the Axis' parent Axes.

lib/matplotlib/projections/polar.py

@@ -431,6 +431,7 @@ class RadialLocator(mticker.Locator):
     scale of the *r*-axis).
     """
 
+    @_api.delete_parameter("3.11", "axes")
     def __init__(self, base, axes=None):
         self.base = base
         self._axes = axes
@@ -440,19 +441,19 @@ def set_axis(self, axis):
 
     def __call__(self):
         # Ensure previous behaviour with full circle non-annular views.
-        if self._axes:
-            if _is_full_circle_rad(*self._axes.viewLim.intervalx):
-                rorigin = self._axes.get_rorigin() * self._axes.get_rsign()
-                if self._axes.get_rmin() <= rorigin:
-                    return [tick for tick in self.base() if tick > rorigin]
+        ax = self.base.axis.axes
+        if _is_full_circle_rad(*ax.viewLim.intervalx):
+            rorigin = ax.get_rorigin() * ax.get_rsign()
+            if ax.get_rmin() <= rorigin:
+                return [tick for tick in self.base() if tick > rorigin]
         return self.base()
 
     def _zero_in_bounds(self):
         """
         Return True if zero is within the valid values for the
         scale of the radial axis.
         """
-        vmin, vmax = self._axes.yaxis._scale.limit_range_for_scale(0, 1, 1e-5)
+        vmin, vmax = self.base.axis._scale.limit_range_for_scale(0, 1, 1e-5)
         return vmin == 0
 
     def nonsingular(self, vmin, vmax):
@@ -681,7 +682,7 @@ def __init__(self, *args, **kwargs):
 
     def set_major_locator(self, locator):
         if not isinstance(locator, RadialLocator):
-            locator = RadialLocator(locator, self.axes)
+            locator = RadialLocator(locator)
         super().set_major_locator(locator)
 
     def clear(self):