Bump mypy from 1.4.1 to 1.6.1 in /requirements (#275)

Bumps [mypy](https://github.com/python/mypy) from 1.4.1 to 1.6.1.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.4.1...v1.6.1)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/requirements-testing.txt

@@ -9,7 +9,7 @@ black==23.7.0
 autoflake==2.2.1
 isort==5.12.0
 flake8==6.0.0
-mypy==1.4.1
+mypy==1.6.1
 
 # other dev stuff
 debugpy==1.8.0