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/relay-chain-rpc-interface/src/reconnecting_ws_client.rs

@@ -125,8 +125,8 @@ async fn connect_next_available_rpc_server(
 		if current_iteration > prev_iteration {
 			// Safe conversion given we convert positive i32s which are lower than u64::MAX.
 			tokio::time::sleep(Duration::from_millis(
-				DEFAULT_SLEEP_TIME_MS_BETWEEN_RETRIES *
-					DEFAULT_SLEEP_EXP_BACKOFF_BETWEEN_RETRIES.pow(prev_iteration) as u64,
+				DEFAULT_SLEEP_TIME_MS_BETWEEN_RETRIES
+					* DEFAULT_SLEEP_EXP_BACKOFF_BETWEEN_RETRIES.pow(prev_iteration) as u64,
 			))
 			.await;
 			prev_iteration = current_iteration;