from https://github.com/elastic/kibana/issues/167992

the error `_id must be unset or set to [GvMPW29fWPE5Sr2ZAAABivq9G6A] but was [_id] because [.ds-metrics-logstash.monitoring-default-2023.10.04-000001] is in time_series mode`

No `_id` field is sent as part of the request so the error must be internal to the endpoint functionality.

This is preventing the creation of runtime fields against TSDS data views in kibana.

--

Steps to reproduce via kibana - 
1. Install `Kibana Sample Data Logs (TSDB)` sample data
2. run via dev tools console
```
POST /_scripts/painless/_execute
{
  "script": {
    "source": """
      emit(doc['release_date'].value.year < 1972);
    """
  },
  "context": "boolean_field",
  "context_setup": {
    "index": "kibana_sample_data_logstsdb",
    "document": {
      "name": "Dune",
      "author": "Frank Herbert",
      "release_date": "1965-06-01",
      "page_count": 604,
      "@timestamp" : "2023-09-16T20:06:26.264Z",
      "bytes_counter": 79635479,
      "bytes_gauge": 8823,
      "event": {
        "dataset": "sample_web_logs"
       }
    }
  }
}
```
modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java
public ContextSetup getContextSetup() {
            return contextSetup;
        }
        @Override
        public ActionRequestValidationException validate() {
            ActionRequestValidationException validationException = null;
            if (script.getType() != ScriptType.INLINE) {
                validationException = addValidationError("only inline scripts are supported", validationException);
            }
            if (needDocumentAndIndex(context)) {
                if (contextSetup.index == null) {
                    validationException = addValidationError("index is a required parameter for current context", validationException);
                }
                if (contextSetup.document == null) {
                    validationException = addValidationError("document is a required parameter for current context", validationException);
                }
            }
            return validationException;
        }
        @Override
        public void writeTo(StreamOutput out) throws IOException {
            super.writeTo(out);
            script.writeTo(out);
            out.writeString(context.name);
            out.writeOptionalWriteable(contextSetup);
        }
        
        @Override
        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
            builder.startObject();