Resolves review comments from pr 134570

Author: garry-cairns

Doc/library/unittest.rst

@@ -1148,7 +1148,7 @@ Test cases
 
       If given, *formatter* should be a :class:`logging.Formatter` object.
       The default is a formatter with
-      ``LOGGING_FORMAT = "%(levelname)s:%(name)s:%(message)s"``
+      ``"%(levelname)s:%(name)s:%(message)s"``
 
       The test passes if at least one message emitted inside the ``with``
       block matches the *logger* and *level* conditions, otherwise it fails.
@@ -1177,7 +1177,7 @@ Test cases
 
       .. versionadded:: 3.4
 
-      .. versionchanged:: 3.15
+      .. versionchanged:: next
          Now accepts a formatter argument so your assertions can match
          a custom format where you are using one.
 

Doc/whatsnew/3.15.rst

@@ -276,7 +276,8 @@ typing
 
 unittest
 --------
-* Expose log formatter to users in TestCase.assertLogs.
+
+* Lets users specify formatter in TestCase.assertLogs.
   :func:`unittest.TestCase.assertLogs` will now accept a formatter
   argument so your assertions can match a custom format where you are using one.
   (Contributed by Garry Cairns in :gh:`134567`.)