Enable Tekton step-actions

This is already enabled and used in Konflux (see
redhat-appstudio/infra-deployments#3693 and
redhat-appstudio/infra-deployments#3818).
Without having the configuration in pipeline-service, updates were
overriding the values. This will not generate diff in Konflux.

operator/gitops/argocd/pipeline-service/openshift-pipelines/tekton-config.yaml

@@ -84,6 +84,7 @@ spec:
     enable-git-resolver: true
     enable-hub-resolver: true
     enable-tekton-oci-bundles: true
+    enable-step-actions: true
     options:
       disabled: false
       configMaps: