restAPI PUT fires on_change with error "Object of type date is not JSON serializable"

Title
frappe.integrations.doctype.webhook.webhook.enqueue_webhook
Error

Traceback (most recent call last):
  File "/home/frappe/frappe-bench/apps/frappe/frappe/utils/background_jobs.py", line 104, in execute_job
    method(**kwargs)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/integrations/doctype/webhook/webhook.py", line 83, in enqueue_webhook
    data = get_webhook_data(doc, webhook)
  File "/home/frappe/frappe-bench/apps/frappe/frappe/integrations/doctype/webhook/webhook.py", line 143, in get_webhook_data
    data = frappe.render_template(webhook.webhook_json, get_context(doc))
  File "/home/frappe/frappe-bench/apps/frappe/frappe/utils/jinja.py", line 86, in render_template
    return get_jenv().from_string(template).render(context)
  File "/home/frappe/frappe-bench/env/lib/python3.7/site-packages/jinja2/environment.py", line 1090, in render
    self.environment.handle_exception()
  File "/home/frappe/frappe-bench/env/lib/python3.7/site-packages/jinja2/environment.py", line 832, in handle_exception
    reraise(*rewrite_traceback_stack(source=source))
  File "/home/frappe/frappe-bench/env/lib/python3.7/site-packages/jinja2/_compat.py", line 28, in reraise
    raise value.with_traceback(tb)
  File "<template>", line 6, in top-level template code
  File "/home/frappe/frappe-bench/env/lib/python3.7/site-packages/jinja2/sandbox.py", line 462, in call
    return __context.call(__obj, *args, **kwargs)
  File "/usr/lib/python3.7/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "/usr/lib/python3.7/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.7/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/usr/lib/python3.7/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type date is not JSON serializable```

https://github.com/frappe/frappe/pull/14340

Expecting to be fixed by this.