Convert models using the fillable property to be "unguarded" with the $guarded = [] property. Depending on your application code, this may create a mass assignment vulnerability.

Before

class Customer extends Model
{
    /**
     * The attributes that are mass assignable.
     *
     * @var string[]
     */
    protected $fillable = ['name', 'email'];
}

After

class Customer extends Model
{
    /**
     * The attributes that aren't mass assignable.
     *
     * @var string[]|bool
     */
    protected $guarded = [];
}