### Description

Tracking total hits sometimes has a non-negligible impact on performance. We should disable it when not strictly required.
x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/execution/search/Querier.java
List<QueryContainer.FieldInfo> refs = query.fields();
            List<HitExtractor> exts = new ArrayList<>(refs.size());
            for (QueryContainer.FieldInfo ref : refs) {
                exts.add(createExtractor(ref.extraction()));
            }
            SearchHitCursor.handle(
                client,
                response,
                source,
                () -> new SchemaSearchHitRowSet(schema, exts, mask, source.size(), query.limit(), response),
                listener,
                query.shouldIncludeFrozen(),
                query.allowPartialSearchResults()
            );
        }
        private HitExtractor createExtractor(FieldExtraction ref) {
            if (ref instanceof SearchHitFieldRef f) {
                return new FieldHitExtractor(f.name(), f.getDataType(), cfg.zoneId(), f.hitName(), multiValueFieldLeniency);
            }
            if (ref instanceof ScriptFieldRef f) {
                return new FieldHitExtractor(f.name(), null, cfg.zoneId(), multiValueFieldLeniency);
            }
            if (ref instanceof ComputedRef computedRef) {
                Pipe proc = computedRef.processor();
                
                Set<String> hitNames = new LinkedHashSet<>();
                proc = proc.transformDown(ReferenceInput.class, l -> {
                    HitExtractor he = createExtractor(l.context());
                    hitNames.add(he.hitName());