Merge pull request #38906 from thaJeztah/carry_38304_fix_swarm_leave_hanging

Fix for situation where swarm leave causes wait forever for agent to stop

daemon/cluster/noderunner.go

@@ -298,6 +298,11 @@ func (n *nodeRunner) Stop() error {
 		n.cancelReconnect = nil
 	}
 	if n.swarmNode == nil {
+		// even though the swarm node is nil we still may need
+		// to send a node leave event to perform any cleanup required.
+		if n.cluster != nil {
+			n.cluster.SendClusterEvent(lncluster.EventNodeLeave)
+		}
 		n.mu.Unlock()
 		return nil
 	}