### Description

Follow-up of #98360: when there is a single filter, the collector could save the overhead of the priority queue (both in `collect()` and `competitiveIterator()`), which would likely result in a speedup.
server/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/FiltersAggregator.java
subAggs,
                keyed,
                keyedBucket
            );
            buckets.add(bucket);
        }
        if (otherBucketKey != null) {
            InternalFilters.InternalBucket bucket = new InternalFilters.InternalBucket(otherBucketKey, 0, subAggs, keyed, keyedBucket);
            buckets.add(bucket);
        }
        return new InternalFilters(name, buckets, keyed, keyedBucket, metadata());
    }
    @Override
    public void collectDebugInfo(BiConsumer<String, Object> add) {
        super.collectDebugInfo(add);
        List<Map<String, Object>> filtersDebug = new ArrayList<>(filters.size());
        for (QueryToFilterAdapter filter : filters) {
            Map<String, Object> debug = new HashMap<>();
            filter.collectDebugInfo(debug::put);
            filtersDebug.add(debug);
        }
        add.accept("filters", filtersDebug);
    }
    /**
     * Collects results by building a {@link LongPredicate} per filter and testing if
     * each doc sent to its {@link LeafBucketCollector} is in each filter
     * which is generally slower than {@link FilterByFilterAggregator} but is compatible
     * with parent and child aggregations.
     */
    static class Compatible extends FiltersAggregator {