Bump more-itertools from 8.2.0 to 8.4.0

Bumps [more-itertools](https://github.com/more-itertools/more-itertools) from 8.2.0 to 8.4.0.
- [Release notes](https://github.com/more-itertools/more-itertools/releases)
- [Commits](more-itertools/more-itertools@v8.2.0...v8.4.0)

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

Author: dependabot[bot]

requirements.txt

@@ -1,6 +1,6 @@
 attrs==19.3.0
 importlib-metadata==1.6.1
-more-itertools==8.2.0
+more-itertools==8.4.0
 packaging==20.3
 parso==0.7.0
 pipdeptree==0.13.2