[fix](nereids) fix LogicalRepeat compute equalset (#47737)

### What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:
This PR addresses an issue where LogicalRepeat should not propagate
equalset because, in scenarios involving group by cube(a, b) with a = b,
LogicalRepeat generates four rows (e.g., when a = b = 3, the rows are
(3,3), (3,null), (null,3), and (null,null)), which breaks the equalset
relationship a = b. To resolve this, the equalset slots are now retained
only when they are part of the common set of LogicalRepeat's group by
keys. This ensures the integrity of equalset is maintained during group
by cube operations, preventing incorrect query results.

fe/fe-core/src/main/java/org/apache/doris/nereids/properties/DataTrait.java

@@ -366,6 +366,10 @@ public void pruneSlots(Set<Slot> outputSlots) {
             fdDgBuilder.removeNotContain(outputSlots);
         }
 
+        public void pruneEqualSetSlots(Set<Slot> outputSlots) {
+            equalSetBuilder.removeNotContain(outputSlots);
+        }
+
         public void replaceUniformBy(Map<Slot, Slot> replaceMap) {
             uniformSet.replace(replaceMap);
         }

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalRepeat.java

@@ -34,9 +34,11 @@
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 
+import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 
 /**
  * LogicalRepeat.
@@ -196,7 +198,16 @@ public void computeUniform(DataTrait.Builder builder) {
 
     @Override
     public void computeEqualSet(DataTrait.Builder builder) {
+        Set<Expression> common = getCommonGroupingSetExpressions();
+        Set<Slot> slots = new HashSet<>();
+        for (Expression expr : common) {
+            if (!(expr instanceof Slot)) {
+                return;
+            }
+            slots.add((Slot) expr);
+        }
         builder.addEqualSet(child().getLogicalProperties().getTrait());
+        builder.pruneEqualSetSlots(slots);
     }
 
     @Override

fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/EliminateGroupByKeyTest.java

@@ -56,6 +56,7 @@ protected void runBeforeAll() throws Exception {
                 + "UNIQUE KEY(id)\n"
                 + "distributed by hash(id) buckets 10\n"
                 + "properties('replication_num' = '1');");
+        createTable("create table test.eli_gbk_t(a int, b int) distributed by hash(a) properties('replication_num'='1');");
         connectContext.setDatabase("test");
         connectContext.getSessionVariable().setDisableNereidsRules("PRUNE_EMPTY_PARTITION");
     }
@@ -179,4 +180,18 @@ void testEliminateByEqual() {
                         agg.getGroupByExpressions().size() == 1
                                 && agg.getGroupByExpressions().get(0).toSql().equals("name")));
     }
+
+    @Test
+    void testRepeatEliminateByEqual() {
+        PlanChecker.from(connectContext)
+                .analyze("select count(1) from (select a,b from eli_gbk_t where a=b group by grouping sets((a,b),(b,a))) t group by a,b;")
+                .rewrite()
+                .printlnTree()
+                .matches(logicalAggregate().when(agg -> agg.getGroupByExpressions().size() == 1));
+        PlanChecker.from(connectContext)
+                .analyze("select count(1) from (select a,b from eli_gbk_t where a=b group by cube(a,b)) t group by a,b;")
+                .rewrite()
+                .printlnTree()
+                .matches(logicalAggregate().when(agg -> agg.getGroupByExpressions().size() == 2));
+    }
 }

regression-test/data/nereids_rules_p0/eliminate_gby_key/eliminate_gby_key.out

@@ -9,3 +9,12 @@
 1
 1
 
+-- !grouping_equalset --
+1
+1
+1
+1
+
+-- !grouping_equalset_can_eliminate --
+2
+

regression-test/suites/nereids_rules_p0/eliminate_gby_key/eliminate_gby_key.groovy

@@ -291,4 +291,6 @@ suite("eliminate_gby_key") {
 	sql "create table eli_gbk_t(a int, b int) distributed by hash(a) properties('replication_num'='1');"
 	sql "insert into eli_gbk_t values(1,1),(2,1),(3,1);"
 	qt_grouping """select count(1) from (select b as k, a k3, sum(b) as sum_k1 from  eli_gbk_t where b=1 group by cube(k,a)) t group by k,k3 order by 1"""
+	qt_grouping_equalset """select count(1) from (select a,b from eli_gbk_t where a=b group by cube(a,b)) t group by a,b;"""
+	qt_grouping_equalset_can_eliminate """select count(1) from (select a,b from eli_gbk_t where a=b group by grouping sets((a,b),(b,a))) t group by a,b;"""
 }