Fix ec2Machines identifier labels.
requested to merge feature/multi_region_support_fix_ec2_machines_tags into feature/multi_region_support_multiple_platforms
Related tasks
Context
The cloudsim-simulation-worker tag added to EC2 instances for bookkeeping purposes had an extra "tag:" prefix, as well as being set on the Labels field (which impacts nodes down the line). Since : is an invalid character for a Kubernetes label, this prevented launched machines from joining the cluster altogether.
Change
The cloudsim-simulation-worker tag has been fixed, and is now being correctly set on the Tags field.