Update Emby for aiohttp v2

[mezz64]

Description:

Update pyEmby library to be compatible with aiohttp version 2.

Checklist:

If the code communicates with devices, web services, or third-party tools:

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass
• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.

[mention-bot]

@mezz64, thanks for your PR! By analyzing the history of the files in this pull request, we identified @fabaff, @balloob and @rmkraus to be potential reviewers.

[balloob]

Thanks!

[balloob]

Cherry-picked into the 0.42 branch