Ensure PipelineRuns created in pending state are handled correctly

[AlanGreene]

Related: tektoncd/pipeline#3522 and docs

Since Tekton Pipelines 0.21 a PipelineRun can be created with status PipelineRunPending and will not begin executing until the status is updated.

To mark a PipelineRun as pending, set .spec.status to PipelineRunPending when creating it:

apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  name: go-example-git
spec:
  # […]
  status: "PipelineRunPending"

To start the PipelineRun, clear the .spec.status field. Alternatively, update the value to PipelineRunCancelled to cancel it.

Verify this is handled correctly in the Dashboard and that we display a suitable status string + icon in this case. This might already be handled by our existing defaults.