Ensure lutron_caseta is only discovered once (#45792)

homeassistant/components/lutron_caseta/config_flow.py

@@ -84,7 +84,9 @@ class LutronCasetaFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
         }
         return await self.async_step_link()
 
-    async_step_homekit = async_step_zeroconf
+    async def async_step_homekit(self, discovery_info):
+        """Handle a flow initialized by homekit discovery."""
+        return await self.async_step_zeroconf(discovery_info)
 
     async def async_step_link(self, user_input=None):
         """Handle pairing with the hub."""