x/build/env/windows: remote desktop client is unreliable on gomote instances.

[cagedmantis]

The use of remote desktop client is inconsistent across all of the Windows builders in the infrastructure.

• If possible, ensure all versions of the Windows builders have RDP enabled.
• Add RDP capability to the GRPC gomote command. This should be enabled by tunneling RDP through SSH. The coordinator SSH server should be modified to enable tunneling.

@golang/release

[cagedmantis]

A possible implementation would be to enable port forwarding on the coordinator's SSH server. An SSH connection could be established with the target gomote instance and then forward the RDP traffic to it.

[gopherbot]

Change https://go.dev/cl/456044 mentions this issue: cmd/gomote: remove legacy gomote functions