Add pytest-asyncio to dependencies to fix azdev test with async tests.

[Qingchuan Hao (mainred)]

Related command

Description

---

This checklist is used to make sure that common guidelines for a pull request are followed.

• pylint azdev --rcfile=.pylintrc -r n

• flake8 --statistics --append-config=.flake8 azdev

[azure-client-tools-bot-prd]

Hi Qingchuan Hao (@mainred),
Please write the description of change into HISTORY.rst.
If you want to release a new azdev version, please update the VERSION in init.py as well.

[Qingchuan Hao (mainred)]

Not sure if we want to install the async test plugin in azdev or simply in the pipeline though.

[gw0] linux -- Python 3.10.18 /mnt/vss/_work/1/s/env/bin/python
async def functions are not natively supported.
You need to install a suitable plugin for your async framework, for example:
  - anyio
  - pytest-asyncio
  - pytest-tornasync
  - pytest-trio
  - pytest-twisted

https://dev.azure.com/azclitools/public/_build/results?buildId=276550&view=logs&jobId=ff866e8d-4875-52ff-9fd3-f181f728432c&j=ff866e8d-4875-52ff-9fd3-f181f728432c&t=64f04c5b-80b8-53a1-8045-e38ac626841b