Migrate from deprecated websocket package

[Jmgr]

Ably-go is currently using golang.org/x/net/websocket as its websocket package. Seeing that this package is now deprecated (see golang/go#18152 and https://pkg.go.dev/golang.org/x/net/websocket) we might want to migrate to another one.

A good alternative could be https://github.com/nhooyr/websocket, as it provides more features (notably the ability to use the browser's WebSockets transparently when targetting wasm, allowing you to write a Go app for the browser that can connect to Ably). Both APIs are not compatible though, so this will require a few code changes.

┆Issue is synchronized with this Jira Uncategorised by Unito

[Rosalita]

Hi @Jmgr I would like to try get this issue back on track.

I can see in the docs for deprecated package that they recommend two packages
https://godoc.org/github.com/gorilla/websocket
https://godoc.org/nhooyr.io/websocket

I can also see that you have a draft PR open here #433 that implements one of those alternatives.

Would it be possible to get your draft PR rebased against latest main branch and ready for review?

[Jmgr]

I have rebased the branch, however some tests are not passing anymore.

[Rosalita]

I've taken a look at the failing test and commented on the PR.

[Rosalita]

Due to issues with existing tests, we need to complete #541 before we can switch the websocket package.