[ECH Agentless] Add support for running multiple versions

[gurevichdmitry]

Motivation

The ECH Agentless workflow currently runs nightly on the main 9.x stack version. To extend coverage, we want to run the same workflow on multiple versions and add support for the 8.x branch, which is currently the main 8.18 version.

Definition of done

• The workflow runs on multiple versions (main (9.x) and 8.x)
• Integration tests are executed as part of the workflow to verify findings retrieval for both types of integrations every 24 hours.
• Workflow will clean up all provisioned resources after tests are done
• Sends Status (Done or Error) to cloud-sec-qa-alerts

Out of scope

• N / A

Related tasks/epics

• [ECH Agentless] Implement workflow for agent-based and agentless Installation on ECH #2862