Cleanup 262 tester and stabilize some experimental features

[jedel1043]

Bumps the test262 repo, cleans up our feature list and stabilizes the experimental features promise-with-resolvers and array-grouping.

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	95,960	96,310	+350
Passed	79,714	79,712	-2
Ignored	3,897	4,217	+320
Failed	12,349	12,381	+32
Panics	0	0	0
Conformance	83.07%	82.77%	-0.30%

Broken tests (4):

test/built-ins/AsyncFromSyncIteratorPrototype/throw/throw-null.js [strict mode] (previously Passed)
test/built-ins/AsyncFromSyncIteratorPrototype/throw/throw-null.js (previously Passed)
test/built-ins/AsyncFromSyncIteratorPrototype/throw/throw-undefined.js [strict mode] (previously Passed)
test/built-ins/AsyncFromSyncIteratorPrototype/throw/throw-undefined.js (previously Passed)

[jedel1043]

Verified that the regressions are because of a normative change in the spec. Will investigate a fix for it.

[HalidOdat]

Looks good to me! :)