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/client/consensus/slots/src/lib.rs

@@ -335,9 +335,9 @@ pub trait SimpleSlotWorker<B: BlockT> {
 
 		let authorities_len = self.authorities_len(&aux_data);
 
-		if !self.force_authoring() &&
-			self.sync_oracle().is_offline() &&
-			authorities_len.map(|a| a > 1).unwrap_or(false)
+		if !self.force_authoring()
+			&& self.sync_oracle().is_offline()
+			&& authorities_len.map(|a| a > 1).unwrap_or(false)
 		{
 			debug!(target: logging_target, "Skipping proposal slot. Waiting for the network.");
 			telemetry!(