I’m not on Windows now, but this should work:
docker run --rm -it --privileged --pid host ubuntu nsenter --all -t 1 qemu-x86_64 --version
My output on Mac:
qemu-x86_64 version 8.1.5 (v8.1.5)
Copyright (c) 2003-2023 Fabrice Bellard and the QEMU Project developer
Explanation: Since the Docker daemon is running in a containr, qemu does not have to be in the PATH in the WSL distro directly. The command I shared runs the qemu command to get the version inside the container in which the Docker daemon is running.
It is, but it is needed in Docker Desktop to be able to emulate arm on amd as well, so it is in Docker Desktop on all platforms. It is of course not the same as the one on macOS which was the legacy virtualization method to run Docker Desktop’s VM itself.