fix(envoy): correct property decorator for devices method

- Added the missing @Property decorator to the devices method in the Envoy class, ensuring proper functionality and access to device information.

Author: JadenFiotto-Kaufman

src/nnsight/intervention/envoy.py

@@ -673,7 +673,7 @@ def device(self) -> Optional[torch.device]:
         except:
             return None
 
-    property
+    @property
     def devices(self) -> Optional[set[torch.device]]:
         """
         Get the devices the module is on. Finds all parameters and return their devices.