Prometheus installation fails with error ''No schedulable nodes found matching node selector for Prometheus - 'region=infra'"

Issue

• The deployment of Prometheus using the Ansible installer fails on the following message:

   fatal: [<hostname>]: FAILED! => {
       "assertion": false,
       "changed": false,
       "evaluated_to": false,
       "failed": true,
       "msg": "No schedulable nodes found matching node selector for Prometheus - 'region=infra'"
   }