Fix: Unbound decorator assertion fires in main deployment

https://gitlab.dev.singlecell.gi.ucsc.edu/ucsc/azul/-/jobs/108572#L550
https://gitlab.anvil.gi.ucsc.edu/ucsc/azul/-/jobs/56224#L510

Regression from 4c6e088

src/azul/chalice.py

@@ -579,7 +579,7 @@ def bind(self, app: Chalice, handler_name: str | None = None) -> Self:
 
         @property
         def tf_function_resource_name(self) -> str:
-            assert self.handler_name is not None, 'Unbound decorator'
+            assert self.app_name is not None, 'Unbound decorator'
             if self.handler_name is None:
                 return self.app_name
             else: