Remove reconciler check for enable-tekton-oci-bundles flag

[lbernick]

Currently, the "bundle" field is only allowed in a v1beta1 TaskRef or PipelineRef if "enable-tekton-oci-bundles" is set to "true". This is validated in the admission webhook.
v1 TaskRefs and PipelineRefs may not contain the "bundle" field.

Prior to this commit, implementation for TaskRefs and PipelineRefs also checked this field. If this field was not set to "true", the PipelineRun and TaskRun reconcilers would attempt to fetch the Pipeline/Task from the cluster instead of from an image registry, which is not correct behavior, and there were no tests for having this flag set to "false" with bundle syntax.

In addition, when we convert from v1beta1 to v1, "bundle" syntax is transformed into bundle resolver syntax. This means when we swap the storage version of the API to v1, the reconciler will stop checking whether the "enable-tekton-oci-bundles" flag is set anyway.

This commit removes this check, fixing the incorrect behavior. The reconciler will correctly reconcile TaskRuns and PipelineRuns with bundle references if they have been accepted by the validation webhook.

/kind bug

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• n/a Has Docs if any changes are user facing, including updates to minimum requirements e.g. Kubernetes version bumps
• Has Tests included if any functionality added or changed
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Release Notes

NONE

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/reconciler/pipelinerun/resources/pipelineref.go	93.8%	93.6%	-0.1
pkg/reconciler/taskrun/resources/taskref.go	90.0%	89.9%	-0.1

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dibyom

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[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage-df to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/reconciler/pipelinerun/resources/pipelineref.go	93.8%	93.6%	-0.1
pkg/reconciler/taskrun/resources/taskref.go	90.0%	89.9%	-0.1

[JeromeJu]

/lgtm
Thanks Lee!