nightly: Bump ICU4X to 2.0 (#4274)

Pre-release

Pre-release

github-actions released this 10 Jun 00:22

5488e93

* Bump ICU to 2.0

* progress

* prog2

* final

* clippy

* fix lints

* fix test regressions

* fix test regressions pt. 2

* fix test regressions pt. 3

* fix test regressions pt. 4

* add TODO for H24

Assets 6