fix(usePersistedStateReducer.test): Fix flaky test of push tab retry

[KaylaBrady]

ticket: https://app.asana.com/0/1148853526253437/1204432665252080/f

I was unable to reproduce the flaky test's failure across 1000+ runs, so it has been tricky confirming if these two changes address the root of the problem, but it seems to me that both of these changes would reduce the likeliness of flaky behavior.

1. awaiting act- this allows us to remove the use of intermediate state variables & waitFor in the tests by waiting until all side effects are resolved. Act is still a bit mysterious to me, but I referenced this explanation linked from the rtl docs for this approach.
2. useRef instead of useState in the usePersistedStateReducer so that updates to routeTabsPushRetriesLeft are synchronous. This prevents a possible race conditions between updating routeTabsPushRetriesLeft and dispatching the retry action.

[github-actions]

Coverage of commit 656984e

Summary coverage rate:
  lines......: 94.8% (2938 of 3100 lines)
  functions..: 74.5% (1221 of 1639 functions)
  branches...: no data found

Files changed coverage rate: n/a

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[lemald]

question: I'm wondering if it would even be possible to simply use a local variable in usePersistedStateReducer rather than a ref, though I haven't thought it all the way through yet and my naive attempt at doing it locally isn't working. This logic is really hard to reason about and I'm hoping there's some way to simplify it a bit further but it might not be possible while fully obeying all of the rules of hooks and everything.

[KaylaBrady]

I haven't been able to get it working using a local variable either - doing some logging in the useEffect, it seems that as a local variable, the value never is decremented. My hunch is that it has do with the local variable being reset when the state returned by useReducer changes and forces a re-render, whereas useRef will persist across re-renders

[github-actions]

Coverage of commit e039e78

Summary coverage rate:
  lines......: 94.8% (2938 of 3100 lines)
  functions..: 74.5% (1221 of 1639 functions)
  branches...: no data found

Files changed coverage rate: n/a

Download coverage report