Remove extraneous TODO comment

src/Discord.Net.Commands/Builders/ModuleClassBuilder.cs

@@ -228,7 +228,6 @@ namespace Discord.Commands
 
             foreach (var attribute in attributes)
             {
-                // TODO: C#7 type switch
                 switch (attribute)
                 {
                     case SummaryAttribute summary:
@@ -302,4 +301,4 @@ namespace Discord.Commands
                    !methodInfo.IsGenericMethod;
         }
     }
-}
+}