force environment timezone

Author: erenkarakal

src/main/java/ch/njol/skript/test/platform/Environment.java

@@ -233,6 +233,7 @@ public TestResults runTests(Path runnerRoot, Path testsRoot, boolean devMode, bo
 			args.add("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8000");
 		args.add("-Duser.language=en");
 		args.add("-Duser.country=US");
+		args.add("-Duser.timezone=UTC");
 		args.addAll(jvmArgs);
 		args.addAll(Arrays.asList(commandLine));