Add the missing token text for TokenKind.QuestionMark (PowerShell#10706)

Author: daxian-dbw

src/System.Management.Automation/engine/parser/token.cs

@@ -1063,8 +1063,8 @@ public static class TokenTraits
             /*                  Shr */ "-shr",
             /*                Colon */ ":",
             /*         QuestionMark */ "?",
-          /* QuestionQuestionEquals */ "??=",
-            /*     QuestionQuestion */ "??",
+            /*    Reserved slot 3   */ string.Empty,
+            /*    Reserved slot 4   */ string.Empty,
             /*    Reserved slot 5   */ string.Empty,
             /*    Reserved slot 6   */ string.Empty,
             /*    Reserved slot 7   */ string.Empty,