RT 5.8 and Fuji X-T4

The RawTherapee nightly builds already include support for the X-T4, which was added by the end of March.

See Adding Support for New Raw Formats - RawPedia
We already have a color matrix from Adobe, but the white levels are missing which would be useful additional information. @barugon @Rick If you can provide the requested images, we can improve the support further for the next release.