Create GHA CI workflow to test k8ssandra-terraform AWS module

[sync-by-unito]

A CI workflow should be created in GHA to test the AWS Terraform module for K8ssandra.
The workflow should be scheduled every week and would provision an EKS cluster on which the latest stable version of K8ssandra would be deployed.
Smoke tests should be implemented to verify that all the components have started successfully:

• Check that the cassdc object reaches "Ready" state
• Check that Cassandra is accessible by running cqlsh
• Check that Stargate is accessible through its REST api
• Check that Reaper is accessible through its REST api
• Check that Grafana is accessible through its Web UI
  Medusa is assumed to be in a working state if Cassandra is accessible.

┆Issue is synchronized with this Jiraserver Task by Unito
┆Epic: k8ssandra-terraform integration tests
┆Issue Number: K8SSAND-574
┆Priority: Medium