Task skopeo-copy's images-url workspace should be optional

[bparry02]

skopeo-copy can operate on a single pair of source and destination images, or a list of images passed via the images-url workspace. The images-url workspace should not be required when only one image should be copied via the srcImageURL and destImageURL parameters.

In task/skopeo-copy/0.4/skopeo-copy.yaml, the workspaces definition should be modified to make the images-url workspace optional:

  workspaces:
    - name: images-url
      optional: true

Expected Behavior

TaskRun succeeds without specifying the unused images-url workspace.

Actual Behavior

[User error] declared workspace "images-url" is required but has not been bound

Steps to Reproduce the Problem

1. Ensure the skopeo-copy task is available
2. Apply the following TaskRun:

---
apiVersion: tekton.dev/v1
kind: TaskRun
metadata:
  name: skopeo-copy-taskrun
spec:
  params:
    - name: srcImageURL
      value: 'docker://registry.access.redhat.com/ubi9/ubi:9.7'
    - name: destImageURL
      value: 'docker://myregistry.acme.com/ubi9/ubi:9.7'
  taskRef:
    kind: Task
    name: skopeo-copy

Additional Info