Remove noop byte cast

Author: nblumhardt

src/Serilog/Parsing/MessageTemplateParser.cs

@@ -228,7 +228,7 @@ static bool TryGetDestructuringHint(char c, out Destructuring destructuring)
         }
     }
 
-    static bool IsValidInFormat(char c) => c != (byte)'}';
+    static bool IsValidInFormat(char c) => c != '}';
 
     static TextToken ParseTextToken(int startAt, string messageTemplate, out int next)
     {