Update mypy requirement from ==0.910 to ==1.8.0

Updates the requirements on [mypy](https://github.com/python/mypy) to permit the latest version.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v0.910...v1.8.0)

---
updated-dependencies:
- dependency-name: mypy
  dependency-type: direct:development
...

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

pyproject.toml

@@ -57,7 +57,7 @@ coverage = ">=4.4"
 jsonpickle = ">1.4.1"
 pytest-cov = ">=2.4.0"
 pytest-mypy = "==0.10.3"
-mypy = "==0.910"
+mypy = "==1.8.0"
 
 
 [tool.poetry.group.contract-tests]