DOC: add note that subplot_mosaic now stable API

tacaswell · tacaswell · commit a27fa2b2700c · 2023-01-06T15:26:34.000-05:00
diff --git a/doc/users/next_whats_new/per_subplot_mosaic.rst b/doc/users/next_whats_new/per_subplot_mosaic.rst
@@ -1,3 +1,11 @@
+``subplot_mosaic`` no longer provisional
+----------------------------------------
+
+The API on `.Figure.subplot_mosaic` and `pyplot.subplot_mosaic` are now
+considered stable and will change under Matplotlib's normal deprecation
+process.
+
+
 Per-subplot keyword arguments  in ``subplot_mosaic``
 ----------------------------------------------------
 
