Disable automatic heap dump on OOM (#6086)

Fixes #5968

Can be re-enabled via `mill-jvm-opts` for any user that wants this back

Author: lihaoyi

runner/launcher/src/mill/launcher/MillProcessLauncher.java

@@ -246,7 +246,6 @@ static List<String> millLaunchJvmCommand(OutFolderMode outMode, String[] runnerC
     // extra opts
     vmOptions.addAll(millJvmOpts(outMode));
 
-    vmOptions.add("-XX:+HeapDumpOnOutOfMemoryError");
     vmOptions.add("-cp");
 
     vmOptions.add(String.join(File.pathSeparator, runnerClasspath));