fix: read error from upload artifacts execution.

What does this MR do?

Fixes a bug when an error occurs during the "artifacts upload" stage.

Why was this MR needed?

During a failure in the upload artifacts step of a build jobs were not failing. This is a problem.

I have tested my patch with a local build and it makes the job fail if an error occurs during artifact uploading execution:

• Example before patch https://gitlab.com/paulrbr/paulrbr.gitlab.io/-/jobs/28482190 (forcing to always return an error on upload artifact)

FATAL: invalid argument                            
Job succeeded

• Example after patch https://gitlab.com/paulrbr/paulrbr.gitlab.io/-/jobs/28483043 (forcing to always return an error on upload artifact)

FATAL: invalid argument                            
ERROR: Job failed: exit code 1

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

Help would be appreciated to create a test case for failed uploads builds.

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Tests
  • Added for this feature/bug
  • All builds are passing
• Branch has no merge conflicts with master (if you do - rebase it please)

What are the relevant issue numbers?

Fixes #2584 (closed)