Flaky test_batch_span_processor_reset_timeout test on windows CI

Describe your environment

Steps to reproduce

tox -f py310-sdk -- -ra --benchmark-json=py310-sdk-windows-2019-benchmark.json

What is the expected behavior?

test passes

What is the actual behavior?

_______ TestBatchSpanProcessor.test_batch_span_processor_reset_timeout ________

self = <tests.trace.export.test_export.TestBatchSpanProcessor testMethod=test_batch_span_processor_reset_timeout>

    @mark.skipif(
        python_implementation() == "PyPy" and system() == "Windows",
        reason="This test randomly fails in Windows with PyPy",
    )
    def test_batch_span_processor_reset_timeout(self):
        """Test that the scheduled timeout is reset on cycles without spans"""
        spans_names_list = []

        export_event = threading.Event()
        my_exporter = MySpanExporter(
            destination=spans_names_list,
            export_event=export_event,
            export_timeout_millis=50,
        )

        span_processor = export.BatchSpanProcessor(
            my_exporter,
            schedule_delay_millis=50,
        )

        with mock.patch.object(span_processor.condition, "wait") as mock_wait:
            resource = Resource.create({})
            _create_start_and_end_span("foo", span_processor, resource)
            self.assertTrue(export_event.wait(2))

            # give some time for exporter to loop
            # since wait is mocked it should return immediately
            time.sleep(0.05)
            mock_wait_calls = list(mock_wait.mock_calls)

            # find the index of the call that processed the singular span
            for idx, wait_call in enumerate(mock_wait_calls):
                _, args, __ = wait_call
                if args[0] <= 0:
                    after_calls = mock_wait_calls[idx + 1 :]
                    break

            self.assertTrue(
>               all(args[0] >= 0.05 for _, args, __ in after_calls)
            )
E           UnboundLocalError: local variable 'after_calls' referenced before assignment

opentelemetry-sdk\tests\trace\export\test_export.py:527: UnboundLocalError

Additional context Add any other context about the problem here.

open-telemetry / opentelemetry-python

Flaky test_batch_span_processor_reset_timeout test on windows CI #3936