Bump ICU4X dependencies to 2.3

[jedel1043]

Stacked on #5489

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	53,125	53,125	0
Passed	51,083	51,083	0
Ignored	1,482	1,482	0
Failed	560	560	0
Panics	0	0	0
Conformance	96.16%	96.16%	0.00%

Fixed tests (2):

test/intl402/DateTimeFormat/prototype/format/bound-to-datetimeformat-instance.js (previously Failed)
test/intl402/Date/prototype/returns-same-results-as-DateTimeFormat.js (previously Failed)

Broken tests (2):

test/intl402/Locale/likely-subtags.js (previously Passed)
test/intl402/Locale/prototype/minimize/removing-likely-subtags-first-adds-likely-subtags.js (previously Passed)

Tested main commit: 14846ead8fff8312fefa50deb6a64ede8584d7f3
Tested PR commit: 519cc9afb8e3a9e0deed7df13b606b6e89219620
Compare commits: 14846ea...519cc9a

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 62.76%. Comparing base (6ddc2b4) to head (519cc9a).
⚠️ Report is 1020 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #5490       +/-   ##
===========================================
+ Coverage   47.24%   62.76%   +15.51%     
===========================================
  Files         476      530       +54     
  Lines       46892    59107    +12215     
===========================================
+ Hits        22154    37096    +14942     
+ Misses      24738    22011     -2727     

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