fix: avoid importing net/http on wasm

[paralin]

Using goweight: https://github.com/paralin/goweight

GOOS=js GOARCH=wasm goweight | less

Without this change:

7.9 MB runtime
6.6 MB net/http
3.1 MB net
3.0 MB crypto/tls
2.0 MB reflect
1.4 MB math/big
1.3 MB crypto/x509
935 kB os
...

With this change:

7.9 MB runtime
3.1 MB net
2.0 MB reflect
935 kB os
...

Slight modifications to avoid importing net/http reduce the binary size significantly.

[nhooyr]

Hi, I understand the reason for this change but unfortunately I cannot merge it as it breaks the API. The API must be kept 1:1 between Go and Wasm and so Dial must return http.Response.

[paralin]

Dial is a global function and the value returned on wasm is a dummy value.

Are people using these in interfaces? is that why? Other than that it seems like anyone using Dial would already be ignoring the dummy value on wasm.

[nhooyr]

People could be wrapping this library in some kind of API/helper for their own code and they might be checking resp or passing it up the chain. This patch would break that.

I don't know if it's common but it doesn't seem far fetched to me. I don't have a better suggestion unfortunately. I'll leave this open for now, let's see if anyone else has thoughts.