### Elasticsearch Version

8.5.0

### Installed Plugins

_No response_

### Java Version

elastic.co customer

### OS Version

elastic.co customer

### Problem Description

Dynamic mapping eagerly interprets a string with this format `2021-51` as a date field, but then fails to index due to 51 not being a valid month.

Expected behaviour would be to index `2021-51` as a text field.

### Steps to Reproduce

With [dynamic mapping](https://www.elastic.co/guide/en/elasticsearch/reference/current/dynamic-mapping.html) turned on attempt to index this document in a fresh, empty index:

```http
POST /bugreport/_doc
{
  "not_a_date": "2022-51"
}
```

Returned error message is:
```json
{
  "error": {
    "root_cause": [
      {
        "type": "date_time_exception",
        "reason": "date_time_exception: Invalid value for MonthOfYear (valid values 1 - 12): 51"
      }
    ],
    "type": "mapper_parsing_exception",
    "reason": "failed to parse field [not_a_date] of type [date] in document with id 'U1f9Y4YBXO70bNmhk658'. Preview of field's value: '2022-51'",
    "caused_by": {
      "type": "date_time_exception",
      "reason": "date_time_exception: Invalid value for MonthOfYear (valid values 1 - 12): 51"
    }
  },
  "status": 400
}
```

### Logs (if relevant)

Mappings on index `bugreport`

```http
GET /bugreport/_mapping
```

```json
{
  "bugreport": {
    "mappings": {}
  }
}
```
server/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java
throw new MapperParsingException(
            "Cannot copy field ["
                + mapper.name()
                + "] to fields "
                + copyToFields
                + ". Copy-to currently only works for value-type fields, not objects."
        );
    }
    private static void parseObject(final DocumentParserContext context, ObjectMapper parentObjectMapper, String currentFieldName)
        throws IOException {
        assert currentFieldName != null;
        Mapper objectMapper = getMapper(context, parentObjectMapper, currentFieldName);
        if (objectMapper != null) {
            context.path().add(currentFieldName);
            if (objectMapper instanceof ObjectMapper objMapper) {
                if (objMapper.subobjects() == false) {
                    context.path().setWithinLeafObject(true);
                }
            }
            parseObjectOrField(context, objectMapper);
            context.path().setWithinLeafObject(false);
            context.path().remove();
        } else {
            parseObjectDynamic(context, parentObjectMapper, currentFieldName);
        }
    }
    private static void parseObjectDynamic(DocumentParserContext context, ObjectMapper parentObjectMapper, String currentFieldName)
        throws IOException {
        ObjectMapper.Dynamic dynamic = dynamicOrDefault(parentObjectMapper, context);
        if (dynamic == ObjectMapper.Dynamic.STRICT) {