Fix and unmute HeapAttack test

Author: julian-elastic

muted-tests.yml

@@ -375,9 +375,6 @@ tests:
 - class: org.elasticsearch.index.mapper.DynamicMappingIT
   method: testConcurrentDynamicIgnoreBeyondLimitUpdates
   issue: https://github.com/elastic/elasticsearch/issues/143326
-- class: org.elasticsearch.xpack.esql.heap_attack.HeapAttackLookupJoinIT
-  method: testLookupExplosionManyMatchesManyFields
-  issue: https://github.com/elastic/elasticsearch/issues/143347
 - class: org.elasticsearch.snapshots.ConcurrentSnapshotsIT
   method: testBackToBackQueuedDeletes
   issue: https://github.com/elastic/elasticsearch/issues/143387

test/external-modules/esql-heap-attack/src/javaRestTest/java/org/elasticsearch/xpack/esql/heap_attack/HeapAttackLookupJoinIT.java

@@ -66,7 +66,7 @@ public void testLookupExplosionManyMatchesManyFields() throws IOException {
         // Streaming lookup processes batches incrementally, keeping memory bounded
         // even with many matches and many fields. Previously threw CircuitBreakerException with the non-streaming path.
         int sensorDataCount = 1500;
-        int lookupEntries = 10000;
+        int lookupEntries = 1000;
         Map<?, ?> map = lookupExplosion(sensorDataCount, lookupEntries, 30, lookupEntries, false);
         assertMap(map, matchesMap().extraOk().entry("values", List.of(List.of(sensorDataCount * lookupEntries))));
     }