Avoid deprecation warning for missing subcommand

Author: marcphilipp

platform-tooling-support-tests/src/test/java/platform/tooling/support/tests/ModularUserGuideTests.java

@@ -145,6 +145,7 @@ private static void junit(Path temp, Writer out, Writer err) throws Exception {
 		command.add("--module");
 		command.add("org.junit.platform.console");
 
+		command.add("execute");
 		command.add("--scan-modules");
 
 		command.add("--config");