Update daskhub's pangeo/base-notebook version to 2025.12.09

Author: jacobtomlinson

daskhub/values.yaml

@@ -57,7 +57,7 @@ jupyterhub:
   singleuser:
     image:
       name: pangeo/base-notebook # Image to use for singleuser environment. Must include dask-gateway.
-      tag: "2025.11.13"
+      tag: "2025.12.09"
     defaultUrl: "/lab" # Use jupyterlab by default.
 
 dask-gateway: