Behave: Remove unused step

Remove unused behave step:
"the user waits for "{process_name}" to finish running"

(cherry picked from commit 3a3a4b70036925fb0ef11354b76fb20461afe931)

gpMgmt/test/behave/mgmt_utils/steps/mgmt_utils.py

@@ -1328,19 +1328,6 @@ def impl(context, filename, output):
         raise Exception(err_str)
 
 
-@then('the user waits for "{process_name}" to finish running')
-def impl(context, process_name):
-    run_command(context, "ps ux | grep `which %s` | grep -v grep | awk '{print $2}' | xargs" % process_name)
-    pids = context.stdout_message.split()
-    while len(pids) > 0:
-        for pid in pids:
-            try:
-                os.kill(int(pid), 0)
-            except OSError:
-                pids.remove(pid)
-        time.sleep(10)
-
-
 @given('the gpfdists occupying port {port} on host "{hostfile}"')
 def impl(context, port, hostfile):
     remote_gphome = os.environ.get('GPHOME')