Verify behavior when calling WithReference to same target multiple times with dev tunnels

Need to verify what happens currently for following examples and update if required:

```csharp
var web = builder.AddProject("web");
var tunnel = builder.AddDevTunnel("tunnel")
.WithReference(web)
.WithReference(web); // Already called for this resource
```

```csharp
var api = builder.AddProject("api");
var tunnel = builder.AddDevTunnel("tunnel")
.WithReference(api);
var web = builder.AddProject("web")
.WithReference(api, tunnel)
.WithReference(api) // Already referencing api but via the tunnel
.WithRefernce(api, tunnel) // Already called this;
```