[kuberay] Test Ray client and update autoscaler image

[DmitriGekhtman]

Why are these changes needed?

This PR adds KubeRay e2e testing for Ray client and updates the suggested autoscaler image to one running the merge commit of PR #23883 .

In more detail, the PR does these things:

• Adds Ray client and dashboard ports to the head service in the example config
• Adds basic testing for Ray client, by modifying the GPU test from #23883 to submit tasks with Ray client
• Updates the autoscaler image to the one from this PR
• Documents context on why we're currently pinning this image
• Allows specifying the autoscaler image in the e2e test
  • I used this to confirm that the pinned autoscaler image is compatible with all Ray images since Ray 1.11.0 -- Ray 1.11.0, Ray 1.11.1 (soon to be released), Ray 1.12.0, and Ray 1.12.1 (soon to be released).

Related issue number

Checks

• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • e2e tests

[Jeffwan]

The change looks good to me!

[DmitriGekhtman]

The change looks good to me!

Thanks for reviewing!

[DmitriGekhtman]

Operator test passes. Test failures unrelated.