Tests: Update legacy arguments passed to `WP_UnitTest_Factory_For_Blog::create_object()`.

This converts the arguments originally meant for `wpmu_create_blog()` to the ones used by `wp_insert_site()`.

Follow-up to [47011].

Fixes #47195.
Built from https://develop.svn.wordpress.org/trunk@47013


git-svn-id: https://core.svn.wordpress.org/trunk@46813 1a063a9b-81f0-0310-95a4-ce76da25c4cd