[VL] Results are mismatch with the vanilla Spark when cast((decmial(20,4)), float)

### Backend

VL (Velox)

### Bug description

```sql
-- Spark
select cast(cast('29925.0000' as decimal(20,4)) as float)
29925.0
Time taken: 2.49 seconds, Fetched 1 row(s)

-- Gluten
select cast(cast('29925.0000' as decimal(20,4)) as float)
29924.998
Time taken: 2.49 seconds, Fetched 1 row(s)
```

### Spark version

None

### Spark configurations

_No response_

### System information

_No response_

### Relevant logs

_No response_