Rubygem-foreman_ansible: unscoped lookupvalue deletion allows cross-model override value destruction

A flaw was found in the foreman_ansible plugin's Ansible override values API. The destroy action resolves the target LookupValue record by ID without verifying it belongs to an AnsibleVariable the caller is authorized to edit. An authenticated user with the edit_ansible_variables permission can delete any LookupValue by ID, including override values for Ansible variables outside their permission filter scope and override values belonging to Puppet smart class parameters.