Hydration re-asks an async memo the server answered with an error, when only isPending of a dependent is read #4375

Found by the async app generator's hydration phase (#4371). Reproduces on next 5f60713. This breaks the no-refetch-on-hydration rule: a read the server answered, with a value or an error, is never asked again by a hydrating client.

const [s] = createSignal(1);
function App() {
  // rejects on the server: 1 + latest(s) + s() = 3
  const m0 = createMemo(() => fetchM0(1 + latest(s) + s()));
  const m1 = createMemo(() => fetchM1(1 + m0()));
  return (
    <main>
      <Errored fallback={e => "[ROOT-E]"}>
        <Loading fallback="[ROOT-L]">
          <span>{String(isPending(m1))}</span>
        </Loading>
      </Errored>
    </main>
  );
}

The server streams m0's rejection (_$HY.r["0"] settles with Error("m0:3")) together with the Loading fragment <span>false</span>. When the client hydrates the shell and that chunk then arrives, it calls fetchM0(3) again for real, outside hydration's dry run. No client write happened before that call.

The generator's minimizer kept the latest(s) dependency: with m0 over s() alone, the case doesn't fail. The page only reads isPending(m1), so no Errored ever sees the error.