Bump aiohttp from 3.8.5 to 3.9.2

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.8.5 to 3.9.2.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst)
- [Commits](aio-libs/aiohttp@v3.8.5...v3.9.2)

---
updated-dependencies:
- dependency-name: aiohttp
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements-dev.txt

@@ -1,4 +1,4 @@
-aiohttp==3.8.5
+aiohttp==3.9.2
 aiohttp_cors==0.7.0
 black==20.8b1
 codecov==2.1.10