[fix](planner)nullable info of agg node's intermediate and output slots should be same

fe/fe-core/src/main/java/org/apache/doris/planner/AggregationNode.java

@@ -374,6 +374,7 @@ public void finalize(Analyzer analyzer) throws UserException {
         List<Expr> groupingExprs = aggInfo.getGroupingExprs();
         for (int i = 0; i < groupingExprs.size(); i++) {
             aggInfo.getOutputTupleDesc().getSlots().get(i).setIsNullable(groupingExprs.get(i).isNullable());
+            aggInfo.getIntermediateTupleDesc().getSlots().get(i).setIsNullable(groupingExprs.get(i).isNullable());
             aggInfo.getOutputTupleDesc().computeMemLayout();
         }
     }

regression-test/data/correctness_p0/test_agg_materialize.out

@@ -6,3 +6,6 @@
 1
 qycs
 
+-- !selectx --
+1	1
+

regression-test/suites/correctness_p0/test_agg_materialize.groovy

@@ -100,4 +100,59 @@ suite("test_agg_materialize") {
                     ORDER BY SPJ.org_code;
                     """
     sql """drop table if exists c5749_bug_t;"""
+
+    sql """drop table if exists table_test_count_distinct;"""
+    sql """CREATE TABLE `table_test_count_distinct` (
+        `special_zone_name` VARCHAR(65532) NULL,
+        `day` VARCHAR(65532) NOT NULL 
+        ) ENGINE=OLAP
+        DUPLICATE KEY(`special_zone_name`)
+        COMMENT 'OLAP'
+        DISTRIBUTED BY HASH(`special_zone_name`) BUCKETS 1
+        PROPERTIES (
+        "replication_allocation" = "tag.location.default: 1"
+        );"""
+    sql """insert into
+            table_test_count_distinct
+            values
+            (
+                'a',
+                "2023-12-01"
+            );"""
+    qt_selectx"""SELECT
+                (COUNT(DISTINCT descript)) as c475859316,
+                (COUNT(DISTINCT day)) as c125327027
+                FROM
+                (
+                    SELECT
+                    descript,
+                    day
+                    FROM
+                    (
+                        with tmp2 as (
+                        select
+                            special_zone_name as descript,
+                            cast(day as datev2) as day
+                        from
+                            table_test_count_distinct
+                        union
+                        all
+                        select
+                            special_zone_name as descript,
+
+                            cast(day as datev2) as day
+                        from
+                            table_test_count_distinct
+                        )
+                        select
+                        t1.descript,
+                        t1.day
+                        from
+                        tmp2 t1
+
+                    ) t665446993
+                ) t1600566476
+                GROUP BY
+                day;"""
+    sql """drop table if exists table_test_count_distinct;"""
 }