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

bizinikiwi/primitives/consensus/babe/src/lib.rs

@@ -311,8 +311,8 @@ where
 
 		// both headers must be targeting the same slot and it must
 		// be the same as the one in the proof.
-		if proof.slot != first_pre_digest.slot() ||
-			first_pre_digest.slot() != second_pre_digest.slot()
+		if proof.slot != first_pre_digest.slot()
+			|| first_pre_digest.slot() != second_pre_digest.slot()
 		{
 			return None;
 		}