bump API version

Author: 1337joe

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,11 +1,14 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 438
+INVENTREE_API_VERSION = 439
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 INVENTREE_API_TEXT = """
 
+v439 -> 2026-01-09 : https://github.com/inventree/InvenTree/pull/11092
+    - Add missing nullable annotations
+
 v438 -> 2026-01-09 : https://github.com/inventree/InvenTree/pull/11104
     - Adds a simpler / faster health check endpoint at /api/system/health/