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/consensus/aura/src/collator.rs

@@ -148,10 +148,11 @@ where
 
 		let paras_inherent_data = match paras_inherent_data {
 			Some(p) => p,
-			None =>
+			None => {
 				return Err(
 					format!("Could not create paras inherent data at {:?}", relay_parent).into()
-				),
+				)
+			},
 		};
 
 		let mut other_inherent_data = self