Fixing weight and declaring it a s final

Signed-off-by: Sandesh Kumar <sandeshkr419@gmail.com>

Author: sandeshkr419

server/src/main/java/org/opensearch/search/aggregations/bucket/terms/GlobalOrdinalsStringTermsAggregator.java

@@ -40,6 +40,7 @@
 import org.apache.lucene.index.SortedSetDocValues;
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
@@ -98,7 +99,7 @@ public class GlobalOrdinalsStringTermsAggregator extends AbstractStringTermsAggr
 
     private final String fieldName;
 
-    private Weight weight;
+    private final Weight weight;
     private final GlobalOrdLookupFunction lookupGlobalOrd;
     protected final CollectionStrategy collectionStrategy;
     protected int segmentsWithSingleValuedOrds = 0;
@@ -151,16 +152,13 @@ public GlobalOrdinalsStringTermsAggregator(
             });
         }
         this.fieldName = ((ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource).getIndexFieldName();
+        this.weight = context.searcher().createWeight(context.query(), ScoreMode.COMPLETE_NO_SCORES, 1f);
     }
 
     String descriptCollectionStrategy() {
         return collectionStrategy.describe();
     }
 
-    public void setWeight(Weight weight) {
-        this.weight = weight;
-    }
-
     /**
      Collects term frequencies for a given field from a LeafReaderContext.
      @param ctx The LeafReaderContext to collect terms from