Bump mypy from 0.971 to 0.981

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] <support@github.com>

requirements-test.txt

@@ -2,7 +2,7 @@
 asynctest~=0.13
 flake8~=5.0
 flake8-docstrings~=1.6
-mypy==0.971
+mypy==0.981
 pylint~=2.15
 pylint-strict-informational==0.1
 pytest~=7.1