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.
const [text, _setText] = useState('Loading...');
        setFallbackText = _setText;
        return <Text text={text} />;
      }
      
      await resolveText('A');
      await ReactNoop.act(async () => {
        root.render(<App />);
      });
      expect(Scheduler).toHaveYielded(['A']);
      expect(root).toMatchRenderedOutput(<span prop="A" />);
      await ReactNoop.act(async () => {
        
        setAppText('B');
        expect(Scheduler).toFlushAndYield(['Suspend! [B]', 'Loading...']);
        
        await advanceTimers(250);
        expect(root).toMatchRenderedOutput(
          <>
            <span hidden={true} prop="A" />
            <span prop="Loading..." />
          </>,
        );
        
        
        
        ReactNoop.discreteUpdates(() => {
          setAppText('C');
        });