Fix DieWithDignity test when waiting on jps (elastic#43861)

the test often hangs on executing jps command
we don't need to wait for this command to finish.

closes elastic#43413

Author: pgomulka

qa/die-with-dignity/src/test/java/org/elasticsearch/qa/die_with_dignity/DieWithDignityIT.java

@@ -34,7 +34,6 @@
 import java.util.List;
 
 import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.not;
 
 public class DieWithDignityIT extends ESRestTestCase {
@@ -49,7 +48,6 @@ public void testDieWithDignity() throws Exception {
         assertBusy(() -> {
             final String jpsPath = PathUtils.get(System.getProperty("runtime.java.home"), "bin/jps").toString();
             final Process process = new ProcessBuilder().command(jpsPath, "-v").start();
-            assertThat(process.waitFor(), equalTo(0));
 
             try (InputStream is = process.getInputStream();
                  BufferedReader in = new BufferedReader(new InputStreamReader(is, "UTF-8"))) {