style: Migrate to stable-only rustfmt configuration

- Remove nightly-only features from .rustfmt.toml and vendor/ss58-registry/rustfmt.toml
- Removed features: imports_granularity, wrap_comments, comment_width,
  reorder_impl_items, spaces_around_ranges, binop_separator,
  match_arm_blocks, trailing_semicolon, trailing_comma
- Format all 898 affected files with stable rustfmt
- Ensures long-term reliability without nightly toolchain dependency

pezcumulus/client/service/src/lib.rs

@@ -244,14 +244,15 @@ pub async fn build_relay_chain_interface(
 			task_manager,
 			hwbench,
 		),
-		pezcumulus_client_cli::RelayChainMode::ExternalRpc(rpc_target_urls) =>
+		pezcumulus_client_cli::RelayChainMode::ExternalRpc(rpc_target_urls) => {
 			build_minimal_relay_chain_node_with_rpc(
 				relay_chain_config,
 				teyrchain_config.prometheus_registry(),
 				task_manager,
 				rpc_target_urls,
 			)
-			.await,
+			.await
+		},
 	}
 }