Additional e2e fixes

[anmazzotti]

This PR is to fix the e2e workflow and bring some improvements.

The turtles-e2e image is now only built once as pre-requisite job. I kept the v0.0.1 tag because changing this has further implications down the line and should be propagated better, for example to the helm chart values and the test/e2e/config/operator.yaml file.

The image is also now deleted correctly always, when all parallel jobs end.
See: https://github.com/rancher/turtles/pkgs/container/turtles-e2e

Sample run: https://github.com/rancher/turtles/actions/runs/12595032471

[furkatgofurov7]

I was checking https://github.com/rancher/turtles/pkgs/container/turtles-e2e and looks like image cleaning failed. Is it unrelated to this PR and can be ignored?

[anmazzotti]

@furkatgofurov7 the cleanup fails because the package has only one version left. GitHub is preventing deletion of that version (even though the error message is super misleading).

Next time it will run the current v0.0.1 version will become untagged, and all follow up cleanups will succeed.
The drawback is that we will have this trailing untagged image as a leftover.

I can experiment further and see if we can delete the entire package, instead of the specific version only, but possibly outside this PR.

I tried to repeat a run: https://github.com/rancher/turtles/actions/runs/12599916400
This time the clean image job succeeds, however one of these tests seem flaky.