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/zombienet/zombienet-sdk/tests/zombie_ci/statement_store.rs

@@ -27,7 +27,9 @@ async fn statement_store() -> Result<(), anyhow::Error> {
 				// type.
 				.with_validator(|node| node.with_name("validator-0"));
 
-			(1..6).fold(r, |acc, i| acc.with_validator(|node| node.with_name(&format!("validator-{i}"))))
+			(1..6).fold(r, |acc, i| {
+				acc.with_validator(|node| node.with_name(&format!("validator-{i}")))
+			})
 		})
 		.with_teyrchain(|p| {
 			p.with_id(2400)