Index template regression when composed of component template with different mapping notations

[piergm]

Description

On 8.11.0+, if we have a component templates that defines a mapping with a different notation than the index template that uses it (dotted notation vs object with property subobject) we get a mapper parsing exception.
A concrete example of this (component template defined as object with property subobject):

PUT _component_template/component-template-test
{
  "template": {
    "mappings": {
      "properties": {
        "object": {
          "properties": {
            "subobject": {
              "type": "keyword"
            }
          }
        }
      }
    }
  }
}

While the index template that uses the component template has in the mapping definition the dotted notation:

POST _index_template/_simulate
{
  "index_patterns": [
    "smops-test-*"
  ],
  "composed_of": [
    "component-template-test"
  ],
  "template": {
    "mappings": {
      "properties": {
        "object.subobject": {
          "type": "version"
        }
      }
    }
  }
}

throws this error:

{
  "error": {
    "root_cause": [
      {
        "type": "illegal_argument_exception",
        "reason": "composable template [simulate_template_nzv683ensognv2oxiqvyca] template after composition with component templates [component-template-test] is invalid"
      }
    ],
    "type": "illegal_argument_exception",
    "reason": "composable template [simulate_template_nzv683ensognv2oxiqvyca] template after composition with component templates [component-template-test] is invalid",
    "caused_by": {
      "type": "illegal_argument_exception",
      "reason": "invalid composite mappings for [simulate_template_nzv683ensognv2oxiqvyca]",
      "caused_by": {
        "type": "mapper_parsing_exception",
        "reason": "Failed to parse mapping: mapper [object.subobject] cannot be changed from type [keyword] to [version]",
        "caused_by": {
          "type": "illegal_argument_exception",
          "reason": "mapper [object.subobject] cannot be changed from type [keyword] to [version]"
        }
      }
    }
  },
  "status": 400
}

The same happens if the dotted notation is used in the component template while the object with property subobject is used in the index template.
This was not the case in versions < 8.11.0. The regression was possibly introduced by #97317

[elasticsearchmachine]

Pinging @elastic/es-search (Team:Search)