[ML] Abort opening job if close is requested during reset

This commit checks if the job has been requested to close after
the reset action completes as part of allocating the job to a new node.
This ensures we do not proceed to start the job process even though
the job had been requested to close.

Closes elastic#74141

Author: dimitris-athanasiou

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/job/task/OpenJobPersistentTasksExecutor.java

@@ -323,6 +323,10 @@ private void revertToCurrentSnapshot(String jobId, ActionListener<Boolean> liste
     }
 
     private void openJob(JobTask jobTask) {
+        if (jobTask.isClosing()) {
+            logger.debug(() -> new ParameterizedMessage("[{}] Aborted opening job as it has been closed", jobTask.getJobId()));
+            return;
+        }
         String jobId = jobTask.getJobId();
         autodetectProcessManager.openJob(jobTask, clusterState, PERSISTENT_TASK_MASTER_NODE_TIMEOUT, (e2, shouldFinalizeJob) -> {
             if (e2 == null) {

x-pack/plugin/src/yamlRestTest/resources/rest-api-spec/test/ml/set_upgrade_mode.yml

@@ -158,9 +158,6 @@ teardown:
 
 ---
 "Setting upgrade mode to disabled from enabled":
-  - skip:
-      version: "all"
-      reason: "AwaitsFix https://github.com/elastic/elasticsearch/issues/74141"
   - do:
       ml.start_datafeed:
         datafeed_id: set-upgrade-mode-job-datafeed