Bump aiohttp from 3.8.1 to 3.8.6 in /integration_tests

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.8.1 to 3.8.6.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst)
- [Commits](aio-libs/aiohttp@v3.8.1...v3.8.6)

---
updated-dependencies:
- dependency-name: aiohttp
  dependency-type: indirect
...

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