chore(test): use make commands in upgrade-test.yml

[puwun]

Description of your changes:

• Added get-last-release-tag, deploy-last-release, and prepare-upgrade make targets
• Updated upgrade-test.yml to use make commands instead of inline shell commands

Fixes: #11704

Checklist:

• You have signed off your commits
• The title for your pull request (PR) should follow our title convention. Learn more about the pull request title convention used in this repository.

[google-oss-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign james-jwu for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[google-oss-prow]

Hi @puwun. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Copilot]

Pull request overview

Refactors the upgrade test GitHub Actions workflow to call reusable Makefile targets instead of duplicating inline shell commands, aligning with issue #11704.

Changes:

• Added Makefile targets to fetch the latest release tag, deploy the last release, and run upgrade-prep tests.
• Updated .github/workflows/upgrade-test.yml to call the new make targets.
• Expanded workflow path filters to rerun when the Makefile changes.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
Makefile	Adds new upgrade-test helper targets used by CI workflow.
.github/workflows/upgrade-test.yml	Switches inline shell to make targets and updates path triggers.