DecodeTest.IccProfileTestXybEncoded fails

Tests should be fixed

The docs seem to imply (unless I'm understanding wrong) that LinearSRGB be/is used when outputting to a floating point format and that SRGB be/is used when outputting to a integer format. however in practice it looks like the same thing ends up getting used for both, meaning that this PR doesn't solve the core issue and instead only shifts the problem around?

https://libjxl.readthedocs.io/en/stable/api_metadata.html#_CPPv4N12JxlBasicInfo21uses_original_profileE

JXL_BOOL uses_original_profile

Whether the data in the codestream is encoded in the original color profile that is attached to the codestream metadata header, or is encoded in an internally supported absolute color space (which the decoder can always convert to linear or non-linear sRGB or to XYB). If the original profile is used, the decoder outputs pixel data in the color space matching that profile, but doesn’t convert it to any other color space. If the original profile is not used, the decoder only outputs the data as sRGB (linear if outputting to floating point, nonlinear with standard sRGB transfer function if outputting to unsigned integers) but will not convert it to to the original color profile. The decoder also does not convert to the target display color profile. To convert the pixel data produced by the decoder to the original color profile, one of the JxlDecoderGetColor* functions needs to be called with JXL_COLOR_PROFILE_TARGET_DATA to get the color profile of the decoder output, and then an external CMS can be used for conversion. Note that for lossy compression, this should be set to false for most use cases, and if needed, the image should be converted to the original color profile after decoding, as described above.