workflow_job_template: no option to specify empty value for webhook_service

[kk-at-redhat]

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Bug Summary

Specifying empty value for webhook_service would be required to disable webhook on a workflow.

AWX version

4.6.7

Select the relevant components

• UI
• UI (tech preview)
• API
• Docs
• Collection
• CLI
• Other

Installation method

docker development environment

Modifications

no

Ansible version

2.15.13

Operating system

RHEL9

Web browser

No response

Steps to reproduce

ansible -m ansible.controller.workflow_job_template --args="name='Workflow B' webhook_service='github'" localhost

localhost | CHANGED => {
"changed": true,
"id": 99
}

ansible -m ansible.controller.workflow_job_template --args="name='Workflow B' webhook_service=''" localhost

Expected results

localhost | CHANGED => {
"changed": true,
"id": 99
}

Actual results

localhost | FAILED! => {
"changed": false,
"msg": "value of webhook_service must be one of: github, gitlab, got: "
}

Additional information

No response