Bump async-timeout from 4.0.0a2 to 4.0.0a3 (#5169)
Bump async-timeout from 4.0.0a2 to 4.0.0a3 (#5169)

Bumps [async-timeout](https://github.com/aio-libs/async_timeout) from 4.0.0a2 to 4.0.0a3.
- [Release notes](https://github.com/aio-libs/async_timeout/releases)
- [Changelog](https://github.com/aio-libs/async-timeout/blob/master/CHANGES.rst)
- [Commits](https://github.com/aio-libs/async_timeout/compare/v4.0.0a2...v4.0.0a3)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
KeepSafe/aiohttp,KeepSafe/aiohttp,KeepSafe/aiohttp