Bump mypy from 1.3.0 to 1.4.0 (#894)

Bumps [mypy](https://github.com/python/mypy) from 1.3.0 to 1.4.0.
- [Commits](python/mypy@v1.3.0...v1.4.0)

---
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>

requirements-dev.txt

@@ -5,7 +5,7 @@ flake8-bandit==4.1.1
 flake8-bugbear==23.6.5
 flake8-import-order==0.18.2
 flake8-requirements==1.7.8
-mypy==1.3.0
+mypy==1.4.0
 pep257==0.7.0
 pre-commit==3.3.3
 sphinx==7.0.1