Remove compareTerm() method in parsed Significant Terms aggregations

This method has been removed in core (see #24714)

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/ParsedSignificantLongTerms.java

@@ -66,11 +66,6 @@ public class ParsedSignificantLongTerms extends ParsedSignificantTerms {
             return key;
         }
 
-        @Override
-        public int compareTerm(SignificantTerms.Bucket other) {
-            return key.compareTo(((ParsedBucket) other).key);
-        }
-
         @Override
         protected XContentBuilder keyToXContent(XContentBuilder builder) throws IOException {
             builder.field(CommonFields.KEY.getPreferredName(), key);

core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/ParsedSignificantStringTerms.java

@@ -67,11 +67,6 @@ public class ParsedSignificantStringTerms extends ParsedSignificantTerms {
             return Double.parseDouble(key.utf8ToString());
         }
 
-        @Override
-        public int compareTerm(SignificantTerms.Bucket other) {
-            return key.compareTo(((ParsedBucket) other).key);
-        }
-
         @Override
         protected XContentBuilder keyToXContent(XContentBuilder builder) throws IOException {
             return builder.field(CommonFields.KEY.getPreferredName(), getKey());