Memory leak on subscriptions

[fbarbat]

As discussed in https://github.com/y-crdt/yswift/pull/44#discussion_r1543872104, running this test causes memory to steadily increase if looking at Activity Monitor.

    func test_allocateTooMany() {
        for i in 1...1000000000 {
            let s = text.observe { _ in }
            text.unobserve(s)
        }
    }

This is pointing to a leak somewhere. I don't know if it is Yswift itself or Yrs.

[heckj]

thanks for opening a new issue with this @fbarbat

[Horusiath]

I'll check it on the yrs side.