Using jxl::extras::Encoder in djxl_ng (#1436)
Using jxl::extras::Encoder in djxl_ng (#1436)

This allows djxl_ng decode to all formats.
libjxl/libjxl,libjxl/libjxl,libjxl/libjxl,libjxl/libjxl,libjxl/libjxl,libjxl/libjxl,libjxl/libjxl,libjxl/libjxl