Removed unused method

Author: costin

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/physical/FilterExec.java

@@ -9,14 +9,12 @@
 import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.xpack.esql.core.expression.Attribute;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.io.stream.PlanStreamInput;
 
 import java.io.IOException;
-import java.util.List;
 import java.util.Objects;
 
 public class FilterExec extends UnaryExec {
@@ -63,11 +61,6 @@ public Expression condition() {
         return condition;
     }
 
-    @Override
-    public List<Attribute> output() {
-        return child().output();
-    }
-
     @Override
     public int hashCode() {
         return Objects.hash(condition, child());