Gradle warns about some methods/properties the plugin uses that they are deprecated and "scheduled to be removed in Gradle 8.0".

JavaExecHandleBuilder.setMain(String) method. Please use the mainClass property instead.
at com.github.maiflai.ScalaTestAction.makeAction(ScalaTestAction.groovy:71)

Report.enabled property. Please use the required property instead.
at com.github.maiflai.ScalaTestAction.getArgs(ScalaTestAction.groovy:165)

Report.destination property. Please use the outputLocation property instead.
at com.github.maiflai.ScalaTestAction.getArgs(ScalaTestAction.groovy:171)