migrate fuzz tests from alpha API versions to v1

[pboyd]

Description

Model registry fuzz tests exercised v1alpha3 and catalog fuzz tests exercised v1alpha1; both are slated for deprecation. Point the Schemathesis fixtures and hard-coded path helpers at the stable v1 specs instead. The v1 model-registry API has no experiment endpoints, so the experiment-specific fuzz tests and helpers are removed.

How Has This Been Tested?

Merge criteria:

• All the commits have been signed-off (To pass the DCO check)

• The commits have meaningful messages
• Automated tests are provided as part of the PR for major new functionalities; testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work.
• Code changes follow the kubeflow contribution guidelines.

[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 ask for approval from pboyd. 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

[pboyd]

Fuzz test run: https://github.com/kubeflow/hub/actions/runs/33673029949