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/utils/pezframe/remote-externalities/src/lib.rs

@@ -1396,8 +1396,8 @@ mod remote_tests {
 
 		// there should be more keys in the child ext.
 		assert!(
-			child_ext.as_backend().backend_storage().keys().len() >
-				ext.as_backend().backend_storage().keys().len()
+			child_ext.as_backend().backend_storage().keys().len()
+				> ext.as_backend().backend_storage().keys().len()
 		);
 	}