Upgrade: bump python-openstackclient in /rootfs/workspace

Bumps [python-openstackclient](https://docs.openstack.org/python-openstackclient/latest/) from 5.8.0 to 6.5.0.

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

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