Describe your environment.
Python 3.8.13 on Linux, opencensus-ext-azure == 1.1.4, azureml-sdk[automl] ~= 1.42.0, azureml-mlflow==1.42.0, mlflow-skinny==1.26.0

Steps to reproduce.
I can't give an exact test code. The problem is related to #1112.
We add an AzureLogHandler on the main thread. Then later we run automl Experiment in multiple threads.

The code in the thread at some point runs import mlflow, and the program stucks.

The import causes to run _configure_mlflow_loggers(root_module_name=__name__), which then runs the logging.config.dictConfig

This runs _clearExistingHandlers in logging.config, and inside of this, the shutdown function runs.
The shutdown runs the following calls for all defined logging handlers:

   h.acquire()
   h.flush()
   h.close()

With previous versions, for example opencensus-ext-azure == 1.1.3 the program stuck at the h.flush() call.
With the 1.1.4 version the h.flush() finishes, but then the run still stops when the self._worker.stop(timeout) is called inside the h.close().

What is the expected behavior?
The import finishes successfully and the program continues

What is the actual behavior?
The program stops in deadlock