Add 'flush ip6tables' task in reset role (#9168)

* Add 'flush ip6tables' task in reset role 

If enable_dual_stack_networks is set to true and ip6 is defined，ip6tables will be created. But when reset the kubernetes cluster, kubespray doesn't flush ip6tables.

* [CI] fix molecule tests on opensuse by upgrading to 15.4 (#9175)

* [CI] fix molecule tests on opensuse by upgrading to 15.4

* [opensuse] use correct python crytography package name depending on distribution version

Co-authored-by: Cristian Calin <6627509+cristicalin@users.noreply.github.com>