MNT: Fix some broken deprecations

The `ngrids` deprecation was missing the version, and style registration
incorrectly included the micro version.

Author: QuLogic

lib/matplotlib/patches.py

@@ -2382,10 +2382,9 @@ def pprint_styles(cls):
 
     @classmethod
     @_api.deprecated(
-        '3.10.0',
+        '3.10',
         message="This method is never used internally.",
-        alternative="No replacement.  Please open an issue if you use this."
-    )
+        alternative="No replacement.  Please open an issue if you use this.")
     def register(cls, name, style):
         """Register a new style."""
         if not issubclass(style, cls._Base):

lib/mpl_toolkits/axes_grid1/axes_grid.py

@@ -190,7 +190,7 @@ def _get_col_row(self, n):
         return col, row
 
     n_axes = property(lambda self: len(self.axes_all))
-    ngrids = _api.deprecated(property(lambda self: len(self.axes_all)))
+    ngrids = _api.deprecated('3.11')(property(lambda self: len(self.axes_all)))
 
     # Good to propagate __len__ if we have __getitem__
     def __len__(self):

lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py

@@ -806,3 +806,5 @@ def test_grid_n_axes():
     fig = plt.figure()
     grid = Grid(fig, 111, (3, 3), n_axes=5)
     assert len(fig.axes) == grid.n_axes == 5
+    with pytest.warns(mpl.MatplotlibDeprecationWarning, match="ngrids attribute"):
+        assert grid.ngrids == 5