Old TODO stating that pkg/cri/opts's `WithWindowsNetworkNamespace`
should be moved to the main containerd pkg was out of date as thats
already been done (well, to the /oci package). This just removes it
and swaps all uses of `WithWindowsNetworkNamespace` to the oci
packages impl.
Signed-off-by: Danny Canter <danny@dcantah.dev>