updating Preparing/Requirements

[FlyingToto]

few questions regarding the documentation on requirements:

@MilosKozak, @peterleimbach,

1. I assume we can add android 13 in the list of supported versions, correct?
2. What about older android version 9 is that still ok from the current branch?
3. is it still possible to use AAPS with versions of Android older than 8 from the old repository with 2.6.1.4?
4. BTW is our documentation still valid for these older builds since we keep updating, devices, screenshots etc...?

Targeted text to refresh :

"The current version of AAPS requires an Android smartphone with Google Android 9.0 or above. So if you are thinking about a new phone, Android 9 is recommended at a minimum but optimally choose Android 10 or 12. Users are strongly encouraged to keep their build of AAPS up to date for safety reason, however for users unable to use a device with a minimum version of Android 8.0, AAPS version 2.6.1.4, suitable for older Android versions, remains available from the old repository."