Enable AV1 support on RTX 40 series GPUs#1803

Add AV1 support because it’s lower file size while same quality as H.264 NVENC for those with RTX 40 series GPUs

Can we also include AMD and Intel AV1 support?

+1 on adding AV1 support, theres no downsides to supporting it. Everything will be AV1 in the future and its just a better encoding format.