plan change from tiflash full scan to index range scan when upgrade to next-gen

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

plan replayer load 'replayer_xm3nY3nWGx72UpQLxpyhyg==_1762947179758778588.zip';

since the below two plan is built from same stats, we should assume that the rows after all filters applied should be quite similar, but we can tell that the rows after all filter applied, is different among this two plan, that's means the count from `selection_48` of tiflash plan and the one from `selection_22` from index lookup plan, they differs.

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


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


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

next-gen and master