Bump aiohttp from 3.7.3 to 3.7.4.post0

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.7.3 to 3.7.4.post0.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/master/CHANGES.rst)
- [Commits](aio-libs/aiohttp@v3.7.3...v3.7.4.post0)

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

test-requirements.txt

@@ -4,7 +4,7 @@
 #
 #    pip-compile test-requirements.in
 #
-aiohttp==3.7.3
+aiohttp==3.7.4.post0
     # via
     #   -r test-requirements.in
     #   pytest-aiohttp