Bump mypy from 1.8.0 to 1.9.0

Bumps [mypy](https://github.com/python/mypy) from 1.8.0 to 1.9.0.
- [Changelog](https://github.com/python/mypy/blob/master/CHANGELOG.md)
- [Commits](python/mypy@v1.8.0...1.9.0)

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

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

requirements/mypy.txt

@@ -1,5 +1,5 @@
 -r postgres.txt
-mypy==1.8.0
+mypy==1.9.0
 mypy-zope==1.0.4
 mysql-connector-python==8.3.0
 types-click==7.1.8