Previously, "nested" calendar property bags were unwrapped up to one
level. That is, this object:
{
calendar: {
// ...Temporal.Calendar methods
}
}
would not be considered to implement the Calendar protocol, but would have
its calendar property used instead, if it were passed to an API that
required a Calendar protocol object.
These nested property bags are no longer supported. Discussion:
https://github.com/tc39/proposal-temporal/issues/2104#issuecomment-1409549753
Corresponding normative PR:
https://github.com/tc39/proposal-temporal/pull/2485
bc979c51a5