[1.12.x] - Don't return validation error when final tasks failed/skipped

Description of problem:

Starting with OpenShift Pipelines 1.11, validation errors are being reported when final task has failed or was skipped. This was not a problem with OpenShift Pipelines 1.10 and earlier.

Details can be found in Pipeline failing with "invalid pipelineresults" when referencing results of skipped tasks and a fix is waiting to be merged via don't return validation error when final tasks failed/skipped.

It's therefore requested to support the ready fix to have it merged in reasonable time and then brought to OpenShift Pipelines 1.11, 1.12 and 1.13 as currently customers are unable to update to OpenShift Pipelines 1.11 or later because of that issue.

Workaround

Prerequisites (if any, like setup, operators/versions):

N/A, there is no workaround and customers are blocked from updating to OpenShift Pipelines 1.11 or later

Steps to Reproduce

 # Please see Pipeline failing with "invalid pipelineresults" when referencing results of skipped tasks

Actual results:

invalid pipelineresults [REPORT_URL], the referred results don't exist

Expected results:

Pipeline to succeed, even final task failed or is skipped

Reproducibility (Always/Intermittent/Only Once):

Always

Acceptance criteria: 

Pipeline to succeed, even final task failed or is skipped

Definition of Done:

Build Details:

OpenShift Pipelines 1.11

Additional info (Such as Logs, Screenshots, etc):