source value 8 is obsolete and will be removed in a future release

Test case:

Kotlin - Build QtQuick4Android project with Qt 6.8 

Outcome:

> Task :app:compileDebugJavaWithJavac
Java compiler version 21 has deprecated support for compiling with source/target version 8.
Try one of the following options:
    1. [Recommended] Use Java toolchain with a lower language version
    2. Set a higher source/target version
    3. Use a lower version of the JDK running the build (if you're not using Java toolchain)
For more details on how to configure these settings, see https://developer.android.com/build/jdks.
To suppress this warning, set android.javaCompile.suppressSourceTargetDeprecationWarning=true in gradle.properties.
warning: [options] source value 8 is obsolete and will be removed in a future release
warning: [options] target value 8 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
3 warnings

Env

• QtGP 1.2 RC
• Host Ubuntu 24.04
• Qt 6.8.2 and 6.9.0 Beta 3
• Android Studio LadyBug Feat drop 2024.2.2 Patch 2
• Pixel 8 Android 14 emulator
• JDK 21.0.5 JetBrains runtime under Android Studio installation