Fix testing against 6.x

Author: jjohannes

build.gradle.kts

@@ -114,5 +114,7 @@ abstract class CapabilityListing : DefaultTask() {
 // === the following custom configuration should be removed once tests are migrated to Java
 apply(plugin = "groovy")
 
+tasks.named<GroovyCompile>("compileTestGroovy") { targetCompatibility = "11" } // allow tests to run against 6.x
+
 dependencies { testImplementation("org.spockframework:spock-core:2.3-groovy-4.0") } //
 // ====================================================================================