Tagged through the following for use by CLDR:
- c7e967c ICU-22401 fix build on MSVC with cpp20
- 2e45e6e ICU-22404 Unicode 15.1 beta data files & API constants
- 5826bf7 ICU-22434 Not calling setFirstDayOfWeek(MONDAY) if the locale has fw
- 034a808 ICU-20898 Improve number skeleton rounding increment docs
- 70d3087 ICU-22325 BRS 74 front-load update version to 74.0.1