Add arm64 linux nightly build

[nekevss]

Hopefully closes #4320.

This adds arm64 linux builds to the nightly CI. I don't really have a good way to check if this does successfully build though.

[jedel1043]

If you want to test this properly, you should add this target to our list of PR targets IMO

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	50,595	50,595	0
Passed	47,259	47,238	-21
Ignored	1,964	1,964	0
Failed	1,372	1,393	+21
Panics	0	0	0
Conformance	93.41%	93.36%	-0.04%

Broken tests (21):

test/built-ins/Temporal/PlainYearMonth/prototype/add/limits.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/overflow-wrong-type.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/overflow-undefined.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/throws-if-year-outside-valid-iso-range.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/order-of-operations.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/argument-object.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/argument-duration-object.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/argument-string.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/options-object.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/add/subclassing-ignored.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/limits.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/overflow-wrong-type.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/overflow-undefined.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/builtin-calendar-no-array-iteration.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/throws-if-year-outside-valid-iso-range.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/order-of-operations.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/argument-object.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/argument-duration-object.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/argument-string.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/options-object.js (previously Passed)
test/built-ins/Temporal/PlainYearMonth/prototype/subtract/subclassing-ignored.js (previously Passed)

[HalidOdat]

Nice addition! Looks good to me! :)