DateTimeFormat/constructor-options-calendar-islamic-fallback.js should allow other fallback values

This test [test/intl402/DateTimeFormat/constructor-options-calendar-islamic-fallback.js](https://github.com/tc39/test262/pull/4627/files#diff-dc5508a559f65908620ea36d9e63761c8139465a129626e08324a97f77bedb13) is incorrect. The defintion of AvailableCalendars in https://tc39.es/proposal-intl-era-monthcode/#sup-availablecalendars is "The [List](https://tc39.es/ecma262/#sec-list-and-record-specification-type) must include the Calendar Type value of every row of [Table 1](https://tc39.es/proposal-intl-era-monthcode/#table-calendar-types), except the header row." It does said it ONLY include those listed in that Table. so the return list may also include "islamic" and "islamic-rgsa" and therefore the test is incorrect.