### 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/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/CsvTestUtils.java
listOfMvValues.add(columnTypes.get(i).convert(mvValue.trim()));
                        }
                        rowValues.add(listOfMvValues);
                    } else {
                        rowValues.add(columnTypes.get(i).convert(value));
                    }
                }
                values.add(rowValues);
            }
            return new ExpectedResults(columnNames, columnTypes, values);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
    public enum Type {
        INTEGER(Integer::parseInt, Integer.class),
        LONG(Long::parseLong, Long.class),
        UNSIGNED_LONG(s -> asLongUnsigned(safeToUnsignedLong(s)), Long.class),
        DOUBLE(Double::parseDouble, Double.class),
        FLOAT(
            
            s -> (double) Float.parseFloat(s),
            Double.class
        ),
        HALF_FLOAT(
            s -> (double) HalfFloatPoint.sortableShortToHalfFloat(HalfFloatPoint.halfFloatToSortableShort(Float.parseFloat(s))),
            Double.class
        ),