Bump mypy from 0.942 to 0.950 (#9691)

Bumps [mypy](https://github.com/python/mypy) from 0.942 to 0.950.
- [Release notes](https://github.com/python/mypy/releases)
- [Commits](python/mypy@v0.942...v0.950)

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

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

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

pyproject.toml

@@ -108,7 +108,7 @@ documentation = "https://docs.saleor.io/"
   pytest-recording = "^0.12.0"
   pytest-xdist = "^2.2.1"
   tox = "^3.23.1"
-  mypy = "^0.942"
+  mypy = "^0.950"
   pywatchman = "^1.4.1"
   types-requests = "^2.25.0"
   types-pytz = "^2021.1.0"