[CI][C++][Flight] Deadlock in GrpcAsyncClientTest.TestListenerLifetime

### Describe the bug, including details regarding any error messages, version, and platform.

This might be an intermittent failure, but it's probably a genuine issue regardless (on the "verify-rc-source-cpp-macos-arm64" nightly build):
https://github.com/ursacomputing/crossbow/actions/runs/6447709893/job/17504243836#step:4:2994

```
[----------] 3 tests from GrpcAsyncClientTest
[ RUN ] GrpcAsyncClientTest.TestGetFlightInfo
[ OK ] GrpcAsyncClientTest.TestGetFlightInfo (9 ms)
[ RUN ] GrpcAsyncClientTest.TestGetFlightInfoFuture
[ OK ] GrpcAsyncClientTest.TestGetFlightInfoFuture (4 ms)
[ RUN ] GrpcAsyncClientTest.TestListenerLifetime
E1008 08:54:18.141345000 6113308672 thd.cc:182] pthread_join failed: Resource deadlock avoided
/private/var/folders/dl/2sqc_b2s20vfy540jn97pz8h0000gn/T/arrow-HEAD.XXXXX.fjmEZkI9/cpp-build/src/arrow/flight
```

### Component(s)

C++, Continuous Integration, FlightRPC