chore: remove unused code.

CanonSharp.Combinator/ParserBuilder.cs

@@ -157,7 +157,7 @@ public static class ParserBuilder
     /// <returns></returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Parser<TToken, T> Choice<TToken, T>(IEnumerable<Parser<TToken, T>> parsers)
-        => parsers.Reverse().Aggregate((next, parser) => parser.Alternative(next));
+        => parsers.Aggregate((result, parser) => result.Alternative(parser));
 
     /// <summary>
     /// 按照给定的解析器组依次尝试
@@ -218,6 +218,5 @@ public static class ParserBuilder
     public static Parser<TToken, IEnumerable<TToken>> Take1Till<TToken, TIgnore>(Parser<TToken, TIgnore> termintor)
         => Any<TToken>().Many1Till(termintor);
 
-
     #endregion
 }