Getting the admin email to be staging compatible

What does this MR do?

This merge request tries to elevate the problem with the admin user that currently only has the username and password available during the runtime. This is a problem for staging as it does not use admin@example.com which in the push_rules_spec was hardcoded.

By getting the email through the api, we are able to use the right one in what ever environment we are in.

Closes #34978 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Style guides
• Separation of EE specific content