Add test for the release

Closes #5317

Author: Pierre-Sassoulas

doc/whatsnew/2.13.rst

@@ -8,6 +8,18 @@
 Summary -- Release highlights
 =============================
 
+In 2.13, we introduced a new check to deal with unicode security issues. On top of that a lot of work was
+done inside the unicode checker by @CarliJoy. We also introduced a new check when importing private name
+and for unnecessary ellipsis among other.
+
+We fixed long standing issues related to duplicate code that could not be disabled, line numbers
+that were not accurate some of the time, and added the ability to lint all files in a directory without
+specifying each one. One of the most anticipated issue from the repository. Thank you @matusvalo !
+
+A lot of ``undefined-variables`` and ``used-before-assignment`` issues were resolved thanks to @jacobtylerwalls.
+
+This release is the last one to support python 3.6.2 whose end of life was reached in december 2021.
+
 New checkers
 ============