OSV-2021-1607 Container-overflow in void jxl::CopyImageTo<int>

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=41235 Crash type: Container-overflow READ 4 Crash state: void jxl::CopyImageTo jxl::ModularFrameDecoder::DecodeGroup jxl::FrameDecoder::ProcessACGroup...