Upgrade to TargetSDK 34

[CampelloManuel]

The play store requires app updates to target SDK version 34 from 31 august 2024. Everything should be ready, and the update should be effortless.

Implementation roadmap:

• [x] update build.gradle for all 3 sub-projects and recompile
• [x] test the app on the emulator and ensure that nothing is broken
• [x] commit and release a full app update

All BEFORE AUGUST 2024!

[CampelloManuel]

implemented in update 7.1.7