Bump mypy from 0.950 to 0.960

Bumps [mypy](https://github.com/python/mypy) from 0.950 to 0.960.
- [Release notes](https://github.com/python/mypy/releases)
- [Commits](python/mypy@v0.950...v0.960)

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

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

Author: dependabot[bot]

test-requirements.txt

@@ -58,7 +58,7 @@ mccabe==0.6.1
     # via
     #   flake8
     #   pylint
-mypy==0.950 ; implementation_name == "cpython"
+mypy==0.960 ; implementation_name == "cpython"
     # via -r test-requirements.in
 mypy-extensions==0.4.3 ; implementation_name == "cpython"
     # via