Add support for running ECH and Serverless test workflows on 8.x versions

[gurevichdmitry]

Summary of your changes

This PR introduces the execution of ECH and Serverless test workflows for the main and 8.x branches. Currently, the jobs run sequentially, but in the future, dependencies can be removed to enable parallel execution.

Changes in this PR:

• Introduced two new workflows:
  • test-runner.yml – Manages execution order and test run permutations.
  • test-e2e-flow.yml – Contains three jobs: setup, deploy (which includes test execution), and destroy.
• Additionally, since the new workflow serves as a common solution for nightly runs, the following workflows will be removed:
  • weekly-serverless.yml
  • test-ech-agentless.yml

Screenshot/Data

This is an example of a workflow run

This is an example of a parallel workflow run

[mergify[bot]]

This pull request does not have a backport label. Could you fix it @gurevichdmitry? 🙏 To fixup this pull request, you need to add the backport labels for the needed branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major. NOTE: backport-v8.x has been added to help with the transition to the new branch 8.x.

[romulets]

What do you mean with dependencies can be removed to enable parallel execution?

[gurevichdmitry]

What do you mean with dependencies can be removed to enable parallel execution?

Currently, in the test-runner, jobs are defined in a sequence: run-ech-8x → needs: run-ech-main, and run-serverless-main → needs: run-ech-8x. Removing these dependencies will allow all jobs to execute in parallel.