Remove unused workflowdata reference and file: (#658)

## Description


This file and reference point to the remove workflowdata API.

## Why is this needed



Fixes: #

## How Has This Been Tested?





## How are existing users impacted? What migration steps/scripts do we need?





## Checklist:

I have:

- [ ] updated the documentation and/or roadmap (if required)
- [ ] added unit or e2e tests
- [ ] provided instructions on how to upgrade

config/crd/kustomization.yaml

@@ -5,7 +5,6 @@ resources:
   - bases/tinkerbell.org_hardware.yaml
   - bases/tinkerbell.org_templates.yaml
   - bases/tinkerbell.org_workflows.yaml
-  - bases/tinkerbell.org_workflowdata.yaml
 #+kubebuilder:scaffold:crdkustomizeresource
 
 # the following config is for teaching kustomize how to do kustomization for CRDs.