build(Gradle): On fail on script compilation warnings

Align with the main compiler settings and also fail the build if
compiler warnings occur in the Gradle Kotlin script build files.

Signed-off-by: Sebastian Schuberth <[email protected]>

Author: sschuberth

gradle.properties

@@ -17,6 +17,7 @@
 
 org.gradle.caching = true
 org.gradle.jvmargs = -Xmx2g -XX:MaxMetaspaceSize=1g -Dfile.encoding=UTF-8
+org.gradle.kotlin.dsl.allWarningsAsErrors = true
 org.gradle.parallel = true
 
 kotlin.code.style = official