Failing QtBuild doesn't block the Java/Kotlin compile task

Steps to reproduce:

1. Make the QtBuild block have a failing configuration, for example change projectPath to a nonexisting directory
2. Gradle sync
3. Run the app

Expected:

    QtBuild fails and blocks any further compilations

Actual:

    QtBuild fails but the Java/Kotlin compilation is attempted, which introduces a lot of failures.

While this is not critical it's probably very confusing for the user, as the IDE shows these errors as the topmost ones.

Checked with Tero that this was not the intention when removing QtAddDependencyTask, so this should be considered to be a regression.