Bump mysql-connector-python from 8.4.0 to 9.0.0 in /requirements

Bumps [mysql-connector-python](http://dev.mysql.com/doc/connector-python/en/index.html) from 8.4.0 to 9.0.0.

---
updated-dependencies:
- dependency-name: mysql-connector-python
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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