Await self_is_synced() (#18772)

Update full_node_simulator.py

chia/simulator/full_node_simulator.py

@@ -747,7 +747,7 @@ async def self_is_synced(self) -> bool:
         return await self.full_node.synced()
 
     async def wallet_is_synced(self, wallet_node: WalletNode, peak_height: Optional[uint32] = None) -> bool:
-        if not self.self_is_synced():
+        if not await self.self_is_synced():
             # Depending on races, may not be covered every time
             return False  # pragma: no cover
         if not await wallet_node.wallet_state_manager.synced():