Remove cluster-wide namespace list/watch permissions
Remove cluster-wide namespace list/watch permissions

This permission was previously needed to support how we enforced
timeouts, by listing all TaskRuns/PipelineRuns across all namespaces and
determining whether they were past their timeout. Since
https://github.com/tektoncd/pipeline/pull/3500/ this check was changed
to not require listing all namespaces, so I believe the permission is no
longer necessary.

tektoncd/pipeline,tektoncd/pipeline