Require appose 0.12 in the StarDist template env

The Java side was updated to Appose 0.12.0; keep the Python side in sync.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: ctrueden

src/main/resources/script_templates/appose-python/cellcast.toml

@@ -10,4 +10,4 @@ python = ">=3.14.3,<3.15"
 
 [pypi-dependencies]
 cellcast = ">=0.1.2, <0.2"
-appose = ">=0.11.0, <0.12"
+appose = ">=0.12.0, <0.13"