[Login] Improve flaky test test_site_address_login_logout

[hafizrahman]

This test keeps randomly failing and succeeding both on iPhone and iPad while working on https://github.com/woocommerce/woocommerce-ios/pull/14309

Further discussion in Slack p1730795587984019-slack-CGPNUU63E , likely related to https://github.com/woocommerce/woocommerce-ios/pull/14225

We need to figure out what's wrong and fix/improve the test.

[dangermattic]

Thanks for reporting! 👍