Fill in release date for 5.0 final

CHANGELOG.txt

@@ -13,7 +13,7 @@ Changelog
  * Maintenance: Switch to ruff for flake8 / isort code checking (Oliver Parker)
 
 
-5.0 (xx.xx.xxxx) - IN DEVELOPMENT
+5.0 (02.05.2023)
 ~~~~~~~~~~~~~~~~
 
  * Added support for Django 4.2

docs/releases/5.0.md

@@ -1,6 +1,6 @@
-# Wagtail 5.0 release notes - IN DEVELOPMENT
+# Wagtail 5.0 release notes
 
-_Unreleased_
+_May 2, 2023_
 
 ```{contents}
 ---