Remove unused method (#118601) (#118773)

I was looking at some type conversion stuff, and noticed this method is never used. Back porting to reduce possible conflicts with the long term maintenance branch later.

Author: not-napoleon

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/planner/TranslatorHandler.java

@@ -12,7 +12,6 @@
 import org.elasticsearch.xpack.esql.core.expression.FieldAttribute;
 import org.elasticsearch.xpack.esql.core.expression.function.scalar.ScalarFunction;
 import org.elasticsearch.xpack.esql.core.querydsl.query.Query;
-import org.elasticsearch.xpack.esql.core.type.DataType;
 
 import java.util.function.Supplier;
 
@@ -34,5 +33,4 @@ default Query wrapFunctionQuery(ScalarFunction sf, Expression field, Supplier<Qu
 
     String nameOf(Expression e);
 
-    Object convert(Object value, DataType dataType);
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/planner/EsqlTranslatorHandler.java

@@ -17,9 +17,7 @@
 import org.elasticsearch.xpack.esql.core.expression.predicate.nulls.IsNull;
 import org.elasticsearch.xpack.esql.core.planner.TranslatorHandler;
 import org.elasticsearch.xpack.esql.core.querydsl.query.Query;
-import org.elasticsearch.xpack.esql.core.type.DataType;
 import org.elasticsearch.xpack.esql.querydsl.query.SingleValueQuery;
-import org.elasticsearch.xpack.esql.type.EsqlDataTypeConverter;
 
 import java.util.function.Supplier;
 
@@ -30,11 +28,6 @@ public Query asQuery(Expression e) {
         return EsqlExpressionTranslators.toQuery(e, this);
     }
 
-    @Override
-    public Object convert(Object value, DataType dataType) {
-        return EsqlDataTypeConverter.convert(value, dataType);
-    }
-
     @Override
     public Query wrapFunctionQuery(ScalarFunction sf, Expression field, Supplier<Query> querySupplier) {
         if (field instanceof FieldAttribute fa) {