See https://github.com/tc39/proposal-temporal/pull/2397 Adds tests for ISO strings with named and numeric offset time zone annotations, with and without the critical flag, with various combinations of Z and offset in front of the annotation.
This copies over the tests that previously existed in the tc39/proposal-temporal repository. For context, see thread starting at: https://github.com/tc39/test262/issues/3002#issuecomment-926234480 In service of https://github.com/tc39/test262/issues/3002