Old binding.type = property template properties aren't removed when updating template

[smbea]

Describe the bug

For template properties with binding type property, if a property is present in "oldTemplate" and not present in "newTemplate" it will not be removed.

We do this for other binding types - ex: inputs - but we don't do it for these.

Steps to reproduce

1. set templates:

v1

{
    "name": "Demo",
    "id": "demo",
    "description": "Demo",
    "version": 1,
    "appliesTo": [
      "bpmn:ServiceTask"
    ],
    "properties": [
      {
        "label": "Implementation Type",
        "type": "Hidden",
        "value": "${demoDelegate}",
        "binding": {
          "type": "property",
          "name": "camunda:delegateExpression"
        }
      }
    ]
  }

v2

 {
   "name": "Demo",
   "id": "demo",
   "description": "Demo",
   "version": 2,
   "appliesTo": [
     "bpmn:ServiceTask"
   ],
   "properties": [
     {
       "label": "Implementation Type",
       "type": "Hidden",
       "value": "external",
       "binding": {
         "type": "property",
         "name": "camunda:type"
       }
     }
   ]
 }

2. apply v1 to a service task -> camunda:delegateExpression is in xml
3. upgrade to v2 -> see that camunda:delegateExpression hasn't been removed

Expected behavior

Old property camunda:delegateExpression should be removed

Environment

• Camunda Modeler Version: latest
• Execution Platform: Camunda Platform

Additional context

Related to SUPPORT-17418

[smbea]

Fixed upstream via bpmn-io/bpmn-js-element-templates#4
Won't be included in 5.13.0 release