Responding with JSON not working after upgrade to version 5.X from 4.X

### Expected Behavior

A JSON response is returned to the caller.

### Actual Behaviour

Exception is thrown.

```
NoSuchMethodError occurred when processing request: [GET] /admin/test
'grails.core.GrailsDomainClassProperty grails.core.GrailsDomainClass.getIdentifier()'. Stacktrace follows:
...
...
Caused by: java.lang.NoSuchMethodError: 'grails.core.GrailsDomainClassProperty grails.core.GrailsDomainClass.getIdentifier()'
at org.grails.web.converters.marshaller.json.DomainClassMarshaller.marshalObject(DomainClassMarshaller.java:116)
at org.grails.web.converters.marshaller.json.DomainClassMarshaller.marshalObject(DomainClassMarshaller.java:52)
at grails.converters.JSON.value(JSON.java:184)
at grails.converters.JSON.convertAnother(JSON.java:144)
at org.grails.web.converters.marshaller.json.CollectionMarshaller.marshalObject(CollectionMarshaller.java:41)
at org.grails.web.converters.marshaller.json.CollectionMarshaller.marshalObject(CollectionMarshaller.java:30)
at grails.converters.JSON.value(JSON.java:184)
```

### Steps To Reproduce

Add the following dependency to a clean grails project:

implementation "org.grails:grails-datastore-rest-client:6.1.12.RELEASE"

The following code produces a no NoSuchMethodError when I call the endpoint:

def getSomething(final Long id) {
respond MyEntity.get(id), formats: ['json']
}

or even easier is:

def test() {
respond "value", formats: ['json']
}

Results in Caused by: org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'value' with class 'java.lang.String' to class 'grails.converters.JSON'.

This is caused by the dependency "org.grails:grails-datastore-rest-client:6.1.12.RELEASE", without it everything works fine. Please advice on a workaround or release a fix for the dependency.

### Environment Information

- Windows
- JDK 15.0.2
- Grails 5.2.1

### Example Application

_No response_

### Version

5.2.1

Start with the stack trace in org.grails.web.converters.marshaller.json.DomainClassMarshaller.java and the related grails.converters.JSON.java calls. Reproduce the failure in the clean Grails project using grails-datastore-rest-client:6.1.12.RELEASE and the getSomething or test endpoint. Done means JSON responses work without the NoSuchMethodError or GroovyCastException when that dependency is present.

Written by the indexing model from the issue text.