status/keyboard: Fix execution order when activating source

When commit ce89b15b made the code async, it did not only delay releasing the keyboard until after the engine has been updated, but also the following code that updates the current input source.

One result is that the current source is now initialized later, which breaks any code that relies on the source being set.

This affects the login screen in particular (which uses different InputSourceSettings than the regular session): It fails to come up entirely if the OSK is enabled.

To fix the issue, update the current source before awaiting the ibus engine update.

Fixes: ce89b15b ("ibusManager: Use async await instead of callbacks") Closes: #7912 (closed)