Prepare 1.12.3 release

Signed-off-by: Kai Hudalla <[email protected]>

Author: sophokles73

site/homepage/content/release-notes.md

@@ -4,7 +4,7 @@ title = "What is new & noteworthy in Hono?"
 description = "Information about changes in recent Hono releases. Includes new features, fixes, enhancements and API changes."
 +++
 
-## 1.12.3 (not yet released)
+## 1.12.3
 
 ### Fixes & Enhancements