fix: skip variadic params in constructors

[Stebalien]

We use them for "options". Ideally we'd be able to forward options through, but that would require real dependency injection.

[marten-seemann]

that would require real dependency injection

How would that look like?

[Stebalien]

This would allow passing options in a "group". We'd have to define a TcpTransport module as follows:

type TcpParams struct {
  fx.In

  Host host.Host
  Upgrader Upgrader
  Options []tcp.Option `group:"tcp_option"`
}

func TcpTransport(params TcpParams) Transport { ... }

type TcpOption struct {
  fx.Out

  Option tcp.Option `group:"tcp_option"`
}

But on second thought, this is even more complicated...

[Stebalien]

Well, the options can be passed as: fx.Supply(fx.Annotated{Group: "tcp_option", MyTcpOption}) and transports could probably be supplied as Transport("tcp", constructor), or something like that. But this is an issue for another day.