Bugfix #8465 - fix: avoid panic when validate enum param with special matrix task was merged into main upstream and cherry pick PRs were created for all necessary Tekton versions for actively-maintained Openshift Pipelines versions. However in the PR for updating Tekton 0.59.x was not automatically merged with the other cherry-picks due to docker-registry rate-limiting causing CI failed. As a result, this fix was included in Openshift Pipelines v1.18.X and other patch versions, however did not make it into Openshift Pipelines v1.15.2 as intended.

vdemeest has rerun the PR's CI and it succeeded. This change should be merged into Tekton 0.59.x and subsequently be included in the next Pipelines 1.15 version, 1.15.3