Bump mypy from 0.971 to 0.981 (#327)

Bumps [mypy](https://github.com/python/mypy) from 0.971 to 0.981.
- [Release notes](https://github.com/python/mypy/releases)
- [Commits](python/mypy@v0.971...v0.981)

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

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

requirements.txt

@@ -1,7 +1,7 @@
 -e .
 build==0.8.0
 docutils==0.19
-mypy==0.971; implementation_name=="cpython"
+mypy==0.981; implementation_name=="cpython"
 pre-commit==2.20.0
 pytest==7.1.3
 pytest-asyncio==0.19.0