Remove object instantiation check

Currently, our standard throw an __error__ if we do something like this:

```php
$date = new DateTime( '2000-01-01', new DateTimeZone( 'Pacific/Nauru' ) );
```

That error comes from the WP CodeSniffer standards, though adhering to that standard is kind of annoying:

```php
$tz = new DateTimeZone( 'Pacific/Nauru' );
$date = new DateTime( '2000-01-01', $tz );
```

This removes the restriction completely.