Update release notes for 3.6.1

Author: QuLogic

doc/_static/switcher.json

@@ -1,6 +1,6 @@
 [
     {
-        "name": "3.6 (stable)",
+        "name": "3.6.1 (stable)",
         "version": "stable",
         "url": "https://matplotlib.org/stable/"
     },

doc/api/next_api_changes/deprecations/24088-JMK.rst

@@ -0,0 +1,15 @@
+API Changes for 3.6.1
+=====================
+
+Deprecations
+------------
+
+Colorbars for orphaned mappables are deprecated, but no longer raise
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Before 3.6.0, Colorbars for mappables that do not have a parent Axes would
+steal space from the current Axes. 3.6.0 raised an error on this, but without a
+deprecation cycle. For 3.6.1 this is reverted; the current Axes is used, but a
+deprecation warning is shown instead. In this undetermined case, users and
+libraries should explicitly specify what Axes they want space to be stolen
+from: ``fig.colorbar(mappable, ax=plt.gca())``.

doc/api/prev_api_changes/api_changes_3.6.1.rst

@@ -15,8 +15,10 @@ Version 3.6
     :maxdepth: 1
 
     prev_whats_new/whats_new_3.6.0.rst
+    ../api/prev_api_changes/api_changes_3.6.1.rst
     ../api/prev_api_changes/api_changes_3.6.0.rst
     github_stats.rst
+    prev_whats_new/github_stats_3.6.0.rst
 
 Version 3.5
 ===========