update ansible dependecy (#7128)

This solves the error "Service is in unknown state" when creating a new Kubernetes installation.
See: https://github.com/ansible/ansible/issues/71528

requirements.txt

-ansible==2.9.6
+ansible==2.9.16
 jinja2==2.11.1
 netaddr==0.7.19
 pbr==5.4.4