Automation: Refactor repository disable/enable test

[yonasberhe23]

Summary

Fixes #rancher/qa-tasks#2053

• Refactor repository disable/enable test to improve retry reliability.
• Moved the failing disable/enable test into its own describe block and split it into separate it blocks: disable, refresh menu validation, and enable.
• The repository is created once via API in the before hook, preventing duplicate creation attempts on retry and avoiding "clusterrepos.catalog.cattle.io ... already exists" errors.
• Each test checks the current state before acting, making them idempotent and retry-safe.

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[izaac]