1. Proposed title of this feature request
TaskRun and PipelineRun should be excluded from ArgoCD by default
2. What is the nature and description of the request?
ArgoCD prunes TaskRun and PipelineRun objects if pipeline is manged by it. To avoid the pruning, an exclusion rule needs to be added explicitly. An example below. The exclusion should happen by default.

  resourceExclusions: |
    - apiGroups:
      - tekton.dev
      clusters:
      - '*'
      kinds:
      - TaskRun
      - PipelineRun 

3. Why does the customer need this? (List the business requirements here)
ArgoCD prunes any PipelineRun object if it manages the Pipeline and it requires exclusion rules in ArgoCD to avoid that. They should be excluded by default.
4. List any affected packages or components.
TaskRun and PipelineRun