UnionExec reports error with static pruning

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Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table if exists t;
create table t(id bigint, datecode bigint, c int, index idx(id, datecode)) partition by range(datecode) (partition p0 values less than (20230501), partition p1 values less than (20230601), partition p2 values less than (20230701));
insert into t values (111111111111111, 20230403, 0), (111111111111111, 20230503, 1), (111111111111111, 20230603, 2);
set tidb_partition_prune_mode='static';
select * from t use index (idx) where id = 111111111111111 and datecode between 20230420 and 20230620 order by datecode limit 2;

2. What did you expect to see? (Required)

query success

3. What did you see instead (Required)

[16:11:33]TiDB root:test> select * from t use index (idx) where id = 111111111111111 and datecode between 20230420 and 20230620 order by datecode limit 2;
(1105, 'Internal error: UnionExec chunk column count mismatch, req: 3, result: 4')

[2023/08/02 16:11:33.528 +08:00] [INFO] [conn.go:1184] ["command dispatched failed"] [conn=2254102191033811351] [connInfo="id:2254102191033811351, addr:127.0.0.1:58937 status:10, collation:utf8_general_ci, user:root"] [command=Query] [status="inTxn:0, autocommit:1"] [sql="select * from t use index (idx) where id = 111111111111111 and datecode between 20230420 and 20230620 order by datecode limit 2"] [txn_mode=PESSIMISTIC] [timestamp=443276038895304705] [err="Internal error: UnionExec chunk column count mismatch, req: 3, result: 4
github.com/pingcap/tidb/executor.(*UnionExec).Next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/executor.go:2007
github.com/pingcap/tidb/executor.Next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/executor.go:326
github.com/pingcap/tidb/executor.(*TopNExec).loadChunksUntilTotalLimit
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/sort.go:440
github.com/pingcap/tidb/executor.(*TopNExec).Next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/sort.go:406
github.com/pingcap/tidb/executor.Next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/executor.go:326
github.com/pingcap/tidb/executor.(*ExecStmt).next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/adapter.go:1202
github.com/pingcap/tidb/executor.(*recordSet).Next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/executor/adapter.go:151
github.com/pingcap/tidb/server.(*tidbResultSet).Next
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/driver_tidb.go:469
github.com/pingcap/tidb/server.(*clientConn).writeChunks
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/conn.go:2313
github.com/pingcap/tidb/server.(*clientConn).writeResultSet
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/conn.go:2256
github.com/pingcap/tidb/server.(*clientConn).handleStmt
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/conn.go:2124
github.com/pingcap/tidb/server.(*clientConn).handleQuery
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/conn.go:1885
github.com/pingcap/tidb/server.(*clientConn).dispatch
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/conn.go:1372
github.com/pingcap/tidb/server.(*clientConn).Run
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/conn.go:1153
github.com/pingcap/tidb/server.(*Server).onConn
	/Users/pingcap/workspace/build-common/go/src/github.com/pingcap/tidb/server/server.go:677
runtime.goexit
	/usr/local/go1.20.5/src/runtime/asm_arm64.s:1172"]

4. What is your TiDB version? (Required)

v7.1.1