Pipelines as Code: enforce hermetic build

As a cluster administrator I want to ensure that all my users are not having any external access when building pipeline to ensure reproducible build.

Note:

• Tekton provides a way to this by annotation https://github.com/tektoncd/pipeline/blob/4db26b168/docs/hermetic.md assuming the api feature is enabled in tekton configmap
• we should update the resolved to add that annotation and making sure to overwrite it if it was already set in user pipeline to whatever it was.