planner: large estimation error for datetime out of range estimation with 20% modified rows

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

Use the plan replayer below to reproduce this issue:

[replayer_quvy7hbtYTPgcuH-v3wufA==_1768830695502317602.zip](https://github.com/user-attachments/files/24759857/replayer_quvy7hbtYTPgcuH-v3wufA._1768830695502317602.zip)

```
id estRows actRows task access object execution info operator info memory disk
Projection_4 1.00 10855 root time:5.56ms, open:88.7µs, close:20.3µs, loops:13, RU:6.33, Concurrency:OFF 1->Column#5 9.49 KB N/A
└─IndexReader_7 1.00 10855 root time:5.42ms, open:80.6µs, close:15.5µs, loops:13, cop_task: {num: 6, max: 1.64ms, min: 268.5µs, avg: 853µs, p95: 1.64ms, max_proc_keys: 2016, p95_proc_keys: 2016, tot_proc: 2.62ms, tot_wait: 242.3µs, copr_cache_hit_ratio: 0.33, build_task_duration: 18.2µs, max_distsql_concurrency: 1}, fetch_resp_duration: 5.15ms, rpc_info:{Cop:{num_rpc:6, total_time:4.95ms}} index:IndexRangeScan_6 56.3 KB N/A
└─IndexRangeScan_6 1.00 10855 cop[tikv] table:Holes, index:idx_Holes_datetime(Holes_datetime) tikv_task:{proc max:7ms, min:0s, avg: 2.17ms, p80:3ms, p95:7ms, iters:34, tasks:6}, scan_detail: {total_process_keys: 3712, total_process_keys_size: 170752, total_keys: 3807, get_snapshot_time: 87.8µs, rocksdb: {key_skipped_count: 3803, block: {cache_hit_count: 28}}}, time_detail: {total_process_time: 2.62ms, total_suspend_time: 4.87µs, total_wait_time: 242.3µs, total_kv_read_wall_time: 3ms, tikv_grpc_process_time: 152.5µs, tikv_grpc_wait_time: 106.8µs, tikv_wall_time: 3.41ms} range:(2024-12-31 00:00:00,+inf], keep order:false N/A N/A
```

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

### 3. What did you see instead (Required)

`1.00 10855`

### 4. What is your TiDB version? (Required)

Master