feat(promise): implement Promise.allKeyed and Promise.allSettledKeyed

[xcb3d]

This Pull Request closes the 12 ignored await-dictionary Test262 tests.

It changes the following:

• Implement Promise.allKeyed() static method per the TC39 await-dictionary proposal
• Implement Promise.allSettledKeyed() static method per the TC39 await-dictionary proposal
• Add shared PerformPromiseAllKeyed algorithm with KeyedVariant enum (All / AllSettled)
• Add CreateKeyedPromiseCombinatorResultObject helper function
• Bump CONSTRUCTOR_STORAGE_SLOTS from 10 to 12
• Remove "await-dictionary" from ignored features in test262_config.toml

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	52,963	52,963	0
Passed	49,902	49,914	+12
Ignored	2,222	2,210	-12
Failed	839	839	0
Panics	0	0	0
Conformance	94.22%	94.24%	+0.02%

Fixed tests (12):

test/built-ins/Promise/allKeyed/length.js (previously Ignored)
test/built-ins/Promise/allKeyed/extensible.js (previously Ignored)
test/built-ins/Promise/allKeyed/proto.js (previously Ignored)
test/built-ins/Promise/allKeyed/name.js (previously Ignored)
test/built-ins/Promise/allKeyed/not-a-constructor.js (previously Ignored)
test/built-ins/Promise/allKeyed/prop-desc.js (previously Ignored)
test/built-ins/Promise/allSettledKeyed/length.js (previously Ignored)
test/built-ins/Promise/allSettledKeyed/extensible.js (previously Ignored)
test/built-ins/Promise/allSettledKeyed/proto.js (previously Ignored)
test/built-ins/Promise/allSettledKeyed/name.js (previously Ignored)
test/built-ins/Promise/allSettledKeyed/not-a-constructor.js (previously Ignored)
test/built-ins/Promise/allSettledKeyed/prop-desc.js (previously Ignored)

Tested main commit: 3c495f236c7598330f48c160b9697d71a29915df
Tested PR commit: cc74b2a75ceb51d89c3a7c3e2aa9e387c42d4c22
Compare commits: 3c495f2...cc74b2a

[codecov]

Codecov Report

❌ Patch coverage is 3.26797% with 148 lines in your changes missing coverage. Please review.
✅ Project coverage is 58.45%. Comparing base (6ddc2b4) to head (cc74b2a).
⚠️ Report is 825 commits behind head on main.

Files with missing lines	Patch %	Lines
core/engine/src/builtins/promise/mod.rs	3.26%	148 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #4996       +/-   ##
===========================================
+ Coverage   47.24%   58.45%   +11.21%     
===========================================
  Files         476      559       +83     
  Lines       46892    61609    +14717     
===========================================
+ Hits        22154    36016    +13862     
- Misses      24738    25593      +855     

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[jedel1043]

All of this needs to be gated behind the experimental feature.

[jedel1043]

Thank you for adding this feature!