Fill in release date for 6.2.2

CHANGELOG.txt

@@ -1,7 +1,7 @@
 Changelog
 =========
 
-6.2.2 (xx.xx.xxxx) - IN DEVELOPMENT
+6.2.2 (24.09.2024)
 ~~~~~~~~~~~~~~~~~~
 
  * Fix: Fix various instances of `USE_THOUSAND_SEPARATOR` formatting numbers where formatting is invalid (Sébastien Corbin, Matt Westcott)

docs/releases/6.2.2.md

@@ -1,6 +1,6 @@
-# Wagtail 6.2.2 release notes - IN DEVELOPMENT
+# Wagtail 6.2.2 release notes
 
-_Unreleased_
+_September 24, 2024_
 
 ```{contents}
 ---