[Automation] CSPM sanity test with cloudformation

### Motivation
The Create-Environment Github workflow creates an EC2 instance with Terraform. Later on, after the creation of agent policy, it ssh into the instance and installs the agent with the required fleet-url and enrollment-token parameters.
Instead, we can use the cloudformation to deploy the CSPM instance as a whole unit.
It will give us more coverage around that flow and we will be able to delete custom code on the test that runs the agent in the instance.

### Definition of done
- [ ] The "Deploy CSPM agent" step should deploy a CloudFormation stack
- [ ] Delete the CSPM EC2 from the Terraform script

### Related tasks/epics
- An example for using cloudformation: https://github.com/elastic/cloudbeat/pull/1076/