Ensure we release tunneld + tunnel binaries

[hh]

We have tested this at https://github.com/cloudnative-coop/wgtunnel/releases/tag/v0.1.13

Will be good to have binaries built for other platforms.

[deansheather]

I don't want to complicate the release process too much. We don't use the tunnel binaries in Coder and only provide the code as an example client. Providing tunnels for each OS and arch combo in releases is potentially more useful but it should be done with actual make targets instead of running make build repeatedly.