GPU access from within a Docker container currently isn't supported on Windows.
You need nvidia-docker, but that is currently only supported on Linux platforms. GPU passthrough with Hyper-v would require Discrete Device Assignment (DDA), which is currently only in Windows Server, and there was no plan to change that state of affairs. Hence, NVIDIA are not porting nvidia-docker to Windows at the moment
A bit more info here: https://devblogs.nvidia/nvidia-docker-gpu-server-application-deployment-made-easy/