How to avoid retry of Async Service Tasks when an OptimisticLockingException occurs

In the BPMN diagram shown below

I have made Task A and Task B as asyncBefore= true and asyncAfter=true without selecting the Exclusive check box.

As i need to run Task A and Task B in a concurrent manner.

When i run the above workflow i often see OptimisticLockingException being thrown and Task A is retried once more.
I am aware of why Optimistic Lock exception is being thrown but i do not want retry of Task A to happen.
How do i avoid retry of Task A in case of OptimisticLock Exception.