chore(deps): bump mypy from 0.971 to 1.6.1 in /dev_requirements

Bumps [mypy](https://github.com/python/mypy) from 0.971 to 1.6.1.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v0.971...v1.6.1)

---
updated-dependencies:
- dependency-name: mypy
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

dev_requirements/coverage-requirements.txt

@@ -1,5 +1,5 @@
 coverage==4.5.4
-mypy==0.971
+mypy==1.6.1
 mypy-extensions==1.0.0
 typing==3.7.4.3
 types-setuptools==63.2.2