Fill in release date for 5.2.2

CHANGELOG.txt

@@ -1,7 +1,7 @@
 Changelog
 =========
 
-5.2.2 (xx.xx.xxxx) - IN DEVELOPMENT
+5.2.2 (06.12.2023)
 ~~~~~~~~~~~~~~~~~~
 
  * Added support for Django 5.0

docs/releases/5.2.2.md

@@ -1,6 +1,6 @@
 # Wagtail 5.2.2 release notes
 
-_Unreleased_
+_December 6, 2023_
 
 ```{contents}
 ---
@@ -23,5 +23,3 @@ This release adds support for Django 5.0.
  * Avoid error when attempting to moderate a page drafted by a now deleted user (Dan Braghis)
  * Ensure workflow dashboard panels work when the page/snippet is missing (Sage Abdullah)
  * Prevent custom controls from stacking on top of the comment button in Draftail toolbar (Ben Morse)
-
-### Documentation