Bump multidict from 4.7.4 to 4.7.6 (#14)

Bumps [multidict](https://github.com/aio-libs/multidict) from 4.7.4 to 4.7.6.
- [Release notes](https://github.com/aio-libs/multidict/releases)
- [Changelog](https://github.com/aio-libs/multidict/blob/master/CHANGES.rst)
- [Commits](https://github.com/aio-libs/multidict/compare/v4.7.4...v4.7.6)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

requirements.txt

@@ -18,7 +18,7 @@ isort==4.3.21
 lazy-object-proxy==1.4.3
 mccabe==0.6.1
 more-itertools==8.2.0
-multidict==4.7.4
+multidict==4.7.6
 mypy==0.782
 mypy-extensions==0.4.3
 packaging==20.3