### Elasticsearch Version

main

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

all

### Problem Description

Do this

### Steps to Reproduce

```
rm /tmp/evil
for a in {0..9}; do
   for b in {0..9}; do
      echo '{"index": {}}' >> /tmp/evil
      echo '{"a": '$a', "b": '$b'}' >> /tmp/evil
   done
done
echo >> /tmp/evil

curl -uelastic:password -XDELETE localhost:9200/test
curl -HContent-Type:application/json -uelastic:password -XPUT localhost:9200/test
curl -HContent-Type:application/json -uelastic:password -XPOST localhost:9200/test/_bulk --data-binary @/tmp/evil
curl -HContent-Type:application/json -uelastic:password -XPOST localhost:9200/test/_forcemerge?max_num_segments=1
curl -HContent-Type:application/json -uelastic:password -XPOST localhost:9200/test/_refresh

curl -HContent-Type:application/json -uelastic:password -XPOST localhost:9200/_esql?pretty -d'{
   "query": "FROM test | STATS MAX(a) BY a, b | KEEP a"
}'
```

### Logs (if relevant)

_No response_
x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/planner/LocalExecutionPlanner.java
Map<String, Integer> fieldToPos = new HashMap<>(extractedFields.size());
        Map<String, ElementType> fieldToType = new HashMap<>(extractedFields.size());
        ElementType[] types = new ElementType[extractedFields.size()];
        for (int i = 0; i < extractedFields.size(); i++) {
            Attribute extractedField = extractedFields.get(i);
            ElementType type = toElementType(extractedField.dataType());
            fieldToPos.put(extractedField.name(), i);
            fieldToType.put(extractedField.name(), type);
            types[i] = type;
        }
        Layout layout = layoutBuilder.build();
        source = source.with(
            new ColumnExtractOperator.Factory(
                types,
                EvalMapper.toEvaluator(grok.inputExpression(), layout),
                () -> new GrokEvaluatorExtracter(grok.pattern().grok(), grok.pattern().pattern(), fieldToPos, fieldToType)
            ),
            layout
        );
        return source;
    }
    private PhysicalOperation planEnrich(EnrichExec enrich, LocalExecutionPlannerContext context) {
        PhysicalOperation source = plan(enrich.child(), context);
        Layout.Builder layoutBuilder = source.layout.builder();
        layoutBuilder.append(enrich.enrichFields());
        Layout layout = layoutBuilder.build();
        Set<String> indices = enrich.enrichIndex().concreteIndices();
        if (indices.size() != 1) {
            throw new EsqlIllegalArgumentException("Resolved enrich should have one concrete index; got " + indices);
        }