[php-src] Issue #20978: OPcode dump of `ZEND_INIT_ARRAY` should not show `(packed)` if OP1 is unused

Issue: https://github.com/php/php-src/issues/20978
Author: TimWolla

### Description

https://github.com/php/php-src/blob/0caebcd1966813dd8ac7546f8e94cb6c83a1d873/ext/standard/tests/array/array_map_foreach_optimization_001.phpt#L34

The `->extended_value` (which holds the `ZEND_ARRAY_NOT_PACKED` flag) is completely ignored when OP1 is unused, making the `(packed)` indicator misleading, since the array will remain uninitalized.

The `(packed)` should either be removed or replaced by something like `(uninit)`.

### PHP Version

```plain
git master
```

### Operating System

_No response_