release-75-rc
ICU-22532 Bump the github-actions group with 9 updates
ICU-22261 Add UCONFIG_NO_MF2 flag that can be used to disable MessageFormat 2 functionality
ICU-22711 Set EnvTest frequency to nightly in March/April/Sept/Oct
ICU-22482 Hash-pin GHA, add dependabot to keep them updated