test: Run gradle build in non parallel fasion. Workaround: jk1/Gradle-License-Report#337

Author: dol

gradle.properties

@@ -1,4 +1,6 @@
-org.gradle.parallel=true
+# Temporaly disable parallel execution due to stability issues observed in CI
+# See https://github.com/jk1/Gradle-License-Report/issues/337
+org.gradle.parallel=false
 org.gradle.caching=true
 org.gradle.configuration-cache=true
 org.gradle.configuration-cache.parallel=true