update SIMD-0222 status and feature gate (#241)

proposals/0222-fix-alt-bn128-multiplication-length-check.md

@@ -5,9 +5,9 @@ authors:
   - Sam Kim
 category: Standard
 type: Core
-status: Review
+status: Implemented
 created: 2025-01-10
-feature:
+feature: bn2puAyxUx6JUabAxYdKdJ5QHbNNmKw8dCGuGCyRrFN
 supersedes:
 superseded-by:
 extends: