Omit NotFound when cleaning up the Affinity Assistant
Omit NotFound when cleaning up the Affinity Assistant

The PipelineRun reconciler cleanup the affinity assistant
when the PipelineRun is completed. If the cleanup-function
is called more than once, the DELETE request will return
a NotFound response. It does not make sense to return NotFound
responses as an error, since this is what we want to achieve.

tektoncd/pipeline,tektoncd/pipeline