fix context bug (#4730)

* fix context bug

Signed-off-by: xinyual <xinyual@amazon.com>

* remove useless stash

Signed-off-by: xinyual <xinyual@amazon.com>

---------

Signed-off-by: xinyual <xinyual@amazon.com>

Author: xinyual

plugin/src/main/java/org/opensearch/ml/action/IndexInsight/GetIndexInsightTransportAction.java

@@ -129,18 +129,7 @@ protected void doExecute(Task task, ActionRequest request, ActionListener<MLInde
                                             );
                                         return;
                                     }
-                                    try (ThreadContext.StoredContext context = client.threadPool().getThreadContext().stashContext()) {
-                                        ActionListener<MLIndexInsightGetResponse> wrappedListener = ActionListener
-                                            .runBefore(actionListener, () -> context.restore());
-                                        executeTaskAndReturn(
-                                            mlIndexInsightGetRequest,
-                                            mlIndexInsightGetRequest.getTenantId(),
-                                            wrappedListener
-                                        );
-                                    } catch (Exception e) {
-                                        log.error("Failed to get index insight", e);
-                                        actionListener.onFailure(e);
-                                    }
+                                    executeTaskAndReturn(mlIndexInsightGetRequest, mlIndexInsightGetRequest.getTenantId(), actionListener);
                                 } catch (Exception e) {
                                     actionListener.onFailure(e);
                                 }