Update query with type boolean

Hi,
I'm having a problem when updating a row with column type of `boolean`, a query that casts a value to `NULL` when that value is `false`.
```
Active bool `json:"active" bun:"active,type:bool,default:'1',nullzero"`
```

```
UPDATE "campaign"
SET "campaign_name" = 'Autodialer 01', "active" = NULL
WHERE 
(campaign_id = 'vaseg')
```

Bun version 1.1.7