Add tests for workspace deletion

[Qxisylolo]

Description

This PR adds tests for workspace deletion, covering three methods:

1. Deleting a workspace using the action button.
2. Deleting one or more workspaces using the multi-delete button.
3. Deleting a workspace from the workspace detail page.

Issues Resolved

[List any issues this PR will resolve]

Check List

• [ ] Commits are signed per the DCO using --signoff

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[SuZhou-Joe]

@Qxisylolo Test cases failed, could you please take a look?