Replaces uses of `webNumbers` with `jsNumbers`.
CoreLibraryReviewExempt: no semantic changes - only updates to use new pkg/expect variations properties
Change-Id: I8072b0b1f92d37e756c211b5d0de106a59d0960b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/346911
Reviewed-by: Mayank Patke <fishythefish@google.com>
