workflow doesn't go ahead next item in case of concurrency: 1

Discussed in https://github.com/StackStorm/st2/discussions/6232

^{Originally posted by freeyssu September 3, 2024}
I usually use with - items statement for parallel process.
I found out that a failed job with concurrency: 1 config causes that task is termiated immediately even though uncompleted items in loop still remains.

This is my sampe code.
When svr1 is failed with concurrency: 1, the workflow doesn 't run the action for the remained 2 items svr2 and svr3. My expectation is that the task completes all 3 items in loop and then mark FAIL result as the first item is failed.
In case of concurrency: 2 or having bigger value, the workflow executes all 3 items and then marks task FAIL result. This is what I expected.

vars
  - servers: ["svr1", "svr2", "svr3"]

task:
    with:
      items: target_server in <% ctx(servers) %>
      concurrency: 1
    action: pack.action    
    next:
      ....
```</div>

Start by reproducing the provided with-items workflow with servers svr1, svr2, and svr3 and concurrency: 1, then trace the workflow task execution path for failed items and concurrency handling. Done means the remaining items still run after the first failure and the task finishes with a failed result; compare this with the existing concurrency: 2 behavior.