fix(store2): "stuck" derived atoms where some derivations may never resolve

[backbone87]

Just a failing test case for:
When an async derived atom picks up a dep asynchronously that never resolves, the derivation never settles even when a subsequent update of the dep does resolve.

I added another test case that demonstrates that picking up the dep synchronously does not lead to this issue

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Name	Status	Preview	Comments	Updated (UTC)
jotai	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 26, 2024 4:19am

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Latest commit: cfd7b88
Last updated: May 26, 2024 4:18am (UTC)

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[dai-shi]

Is it even fixable? Feel free to try.

[backbone87]

the problem is that async deps are only recognized by store once the derivation settles. imho all deps should be recognized and tracked as soon as they occur. a consistent read would also be nice, e.g.

async (get) => {
  const a = get(anAtom);
  await delay(someTime);
  assert(a === get(anAtom));
}

[dai-shi]

that's kind of by design: collect deps once in sync and once when settled. it's a computational task, and so it might require some tricks to cover more cases.
So, I'd say, it's currently a design limitation.

[dai-shi]

Thanks for the nice tests. The "sync" version actually reveals a bug in store2.ts.