Add version details in ellipse annotation docstring

Co-authored-by: Oscar Gustafsson <[email protected]>

Author: ckcherry23

lib/matplotlib/patches.py

@@ -2342,7 +2342,11 @@ def __call__(self, x0, y0, width, height, mutation_size):
 
     @_register_style(_style_list)
     class Ellipse:
-        """An elliptical box."""
+        """
+        An elliptical box.
+        
+        .. versionadded:: 3.7
+        """
 
         def __init__(self, pad=0.3):
             """