Column type bigint generates a non existing `z.int8()` method

## Expected Behavior
Not sure, z.bigint or z.number ?

## Actual Behavior
```ts
row_nbr: z.int8().nullable().optional(),
```

## Steps to Reproduce the Problem
Create a bigint column, generate types.

## Specifications

- Version: pgzod@3.3.0
- Platform: PostgreSQL (ver. 15.5 (Debian 15.5-1.pgdg120+1)
