Wait for axios mock in spec

What does this MR do?

@vue/test-utils is changing its internal implementation to sync operation in certain scenarios.

This forces us to explicitly wait for promises to resolve (promise we're waiting for is:

mockAxios.onPost(validateQueryPath).reply(validQueryResponse);

Closes #122859 (closed)

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content