Bump mypy from 1.1.1 to 1.2.0 in /requirements (AtsushiSakai#816)

Bumps [mypy](https://github.com/python/mypy) from 1.1.1 to 1.2.0.
- [Release notes](https://github.com/python/mypy/releases)
- [Commits](python/mypy@v1.1.1...v1.2.0)

---
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>

Author: dependabot[bot]

requirements/requirements.txt

@@ -4,5 +4,5 @@ matplotlib == 3.7.1
 cvxpy == 1.3.1
 pytest == 7.3.0 # For unit test
 pytest-xdist == 3.2.1 # For unit test
-mypy == 1.1.1 # For unit test
+mypy == 1.2.0 # For unit test
 ruff == 0.0.261 # For unit test