feat(pruner): add default resource limits to controller and webhook

[infernus01]

Summary

Adds default resource requests and limits for tekton-pruner-controller and tekton-pruner-webhook deployments in the operator.

Changes

Modified pkg/reconciler/kubernetes/tektonpruner/transform.go to include a new addDefaultResourceLimits() transformer that injects default
resource specifications:

tekton-pruner-controller

resources:
  requests:
    cpu: 100m
    memory: 256Mi
  limits:
    cpu: 500m
    memory: 2Gi

tekton-pruner-webhook

  resources:
    requests:
      cpu: 50m
      memory: 64Mi
    limits:
      cpu: 250m
      memory: 128Mi

Rationale

Benchmark data: Testing showed the pruner controller uses 846-1126 MB heap memory when tracking 26k-38k resident PipelineRuns in its informer cache.

Override Mechanism

These defaults can be overridden via TektonConfig or TektonPruner CR:

  apiVersion: operator.tekton.dev/v1alpha1
  kind: TektonConfig
  spec:
    pruner:
      options:
        deployments:
        - name: tekton-pruner-controller
          spec:
            template:
              spec:
                containers:
                - name: controller
                  resources:
                    limits:
                      memory: 4Gi  # Override default

The transformer runs before the options transformer, so user-specified values take precedence.

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Release Notes

NONE

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 26.89%. Comparing base (f09782c) to head (ff5b47f).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4066      +/-   ##
==========================================
- Coverage   26.95%   26.89%   -0.06%     
==========================================
  Files         467      467              
  Lines       25170    25225      +55     
==========================================
  Hits         6785     6785              
- Misses      17648    17703      +55     
  Partials      737      737              

Flag	Coverage Δ
unit-tests	26.89% <ø> (-0.06%)	⬇️

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[pratap0007]

can you please move this entire loop into a common function?