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/pezframe/nomination-pools/fuzzer/src/call.rs

@@ -267,8 +267,8 @@ fn main() {
 				}
 
 				// execute sanity checks at a fixed interval, possibly on every block.
-				if iteration %
-					(std::env::var("SANITY_CHECK_INTERVAL")
+				if iteration
+					% (std::env::var("SANITY_CHECK_INTERVAL")
 						.ok()
 						.and_then(|x| x.parse::<u64>().ok()))
 					.unwrap_or(1) == 0