async_substrate.py: drop superfluous init of self.registry

Author: µ

async_substrate_interface/async_substrate.py

@@ -2548,7 +2548,6 @@ async def runtime_call(
             params = {}
 
         try:
-            self.registry = PortableRegistry.from_metadata_v15(self.metadata_v15)
             metadata_v15_value = self.metadata_v15.value()
 
             apis = {entry["name"]: entry for entry in metadata_v15_value["apis"]}