Append trace chunk only if job is running

What does this MR do?

As per @ayufan 's nice suggestion

it is probably, that we allow to append only running ones, not canceled ones So maybe we should change the rule

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/46383

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Conform by the code review guidelines
  • Has been reviewed by a Backend maintainer
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Related: https://gitlab.com/gitlab-org/gitlab-ce/issues/46097