[BUG]: isNotNull does not impact type of returned column

### What version of `drizzle-orm` are you using?

0.33.0

### What version of `drizzle-kit` are you using?

0.24.2

### Describe the Bug

Say you have this schema

```
export const user = pgTable("user", {
name: varchar("name").notNull(),
age: integer("age").notNull(),
})

export const pet = pgTable("pet", {
name: varchar("name").notNull(),
age: integer("age")
})

```

And you want to combine two queries like this:

```
const humanAge=db.select({age:user.age}).from(user)
const animalAge = db.select({age:pet.age}).from(pet).where(isNotNull(pet.age))

const age = union(humanAge,animalAge)

```

Even though we ensured that age can never be null (`isNotNull...`), Typescript complains: ```Type 'number | null' is not assignable to type 'number' ```

### Expected behavior

{ age: number }

### Environment & setup

_No response_