test(cdk/listbox): remove unnecessary async from tests (#25829)

The `compileComponents` calls don't need to be `await`-ed unless the component has an external template or stylesheet. These changes remove all of the async/await, as well as the `waitForAsync` wrappers since they're likely the source of some of the deprecation warnings that are being logged.

(cherry picked from commit c2fb961)

Author: crisbeto