Has several effects on existing tests:
- Remove PlainTime from various tests that extract a Temporal.Calendar
instance from another Temporal object.
- Remove Temporal.PlainTime.prototype.calendar property.
- Remove calendar property from object returned from
Temporal.PlainTime.prototype.getISOFields().
- Ignore calendar annotation when converting ISO string to PlainTime.
Normative PR: https://github.com/tc39/proposal-temporal/pull/2482