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

pezkuwi/node/subsystem-bench/src/lib/availability/mod.rs

@@ -220,13 +220,14 @@ pub fn prepare_test(
 	let (overseer, overseer_handle) = match &mode {
 		TestDataAvailability::Read(options) => {
 			let subsystem = match options.strategy {
-				Strategy::FullFromBackers =>
+				Strategy::FullFromBackers => {
 					AvailabilityRecoverySubsystem::with_recovery_strategy_kind(
 						collation_req_receiver,
 						&state.req_protocol_names,
 						Metrics::try_register(&dependencies.registry).unwrap(),
 						RecoveryStrategyKind::BackersFirstAlways,
-					),
+					)
+				},
 				Strategy::Chunks => AvailabilityRecoverySubsystem::with_recovery_strategy_kind(
 					collation_req_receiver,
 					&state.req_protocol_names,
@@ -436,8 +437,8 @@ pub async fn benchmark_availability_write(
 				.get(index)
 				.expect("all validators have keys");
 
-			if env.network().is_peer_connected(peer) &&
-				env.network().send_request_from_peer(peer, request).is_ok()
+			if env.network().is_peer_connected(peer)
+				&& env.network().send_request_from_peer(peer, request).is_ok()
 			{
 				Some(pending_response_receiver)
 			} else {