Repro case with a master build: https://codesandbox.io/s/stoic-mcnulty-dhygf?file=/src/App.js:668-703

Expected: we see content after a second.
Actual: fallback never resolves.

This happens in a sequence of:

1. Normal update
   - which suspends
2. Idle update
   - which also suspends
3. An unrelated normal update immediately followed by a ping (so they're batched)
   - here, we decide to stay on fallback, but should've shown the content

If you remove `_setVersion(v => v + 1);` on line 44 then the issue goes away.
expect(ReactNoop.getChildren()).toEqual([span('B')]);
    Scheduler.unstable_advanceTime(1200);
    await advanceTimers(1200);
    
    expect(ReactNoop.getChildren()).toEqual([span('B')]);
    Scheduler.unstable_advanceTime(60000);
    await advanceTimers(60000);
    
    expect(ReactNoop.getChildren()).toEqual([
      hiddenSpan('B'),
      span('Loading...'),
    ]);
  });
  
  it('withSuspenseConfig timeout applies when we use an updated avoided boundary', async () => {
    function App({page}) {
      return (
        <Suspense fallback={<Text text="Loading..." />}>
          <Text text="Hi!" />
          <Suspense
            fallback={<Text text={'Loading ' + page + '...'} />}
            unstable_avoidThisFallback={true}>
            <AsyncText text={page} ms={3000} />
          </Suspense>
        </Suspense>
      );
    }
    
    ReactNoop.render(<App page="A" />);
    expect(Scheduler).toFlushAndYield(['Hi!', 'Suspend! [A]', 'Loading...']);