Based on this comment:
https://github.com/openshift/openshift-docs/pull/60644#discussion_r1217664689
there are many instances in the Pipelines as Code documentation, where we refer to the default namespace as `pipelines-as-code` and use it in the code snippets as well.
however, for downstream version, the namespace is actually `openshift-pipelines`. Therefore, we need to correct the namespace for the chapter to fix the inconsistency.