Arrays - Multiple Files Upload - Delete Parent Array Element Where Child Array ['error'] => 4

Here is my code:

HTML (Multiple Uploads):

<input type="file" name="attached_photo_1" id="attached_photo_1" />
<input type="file" name="attached_photo_2" id="attached_photo_2" />
<input type="file" name="attached_photo_3" id="attached_photo_3" />
<input type="file" name="attached_photo_4" id="attached_photo_4" />
<input type="file" name="attached_photo_5" id="attached_photo_5" />

PHP

$photo_array = array( 
  $_FILES['attached_photo_1'], 
  $_FILES['attached_photo_2'], 
  $_FILES['attached_photo_3'],
  $_FILES['attached_photo_4'],
  $_FILES['attached_photo_5']
);

Example

Now lets say someone only uploaded images for photo 1 and 2, leaving images 3, 4, and 5 with a $_FILES error code of 4 (meaning no file was uploaded).

Example Output (using <?php print_r($photo_array); ?>):

Array
(
    [0] => Array
        (
            [name] => test.png
            [type] => image/png
            [tmp_name] => /Applications/XAMPP/xamppfiles/temp/php0JwXJc
            [error] => 0
            [size] => 3469655
        )

    [1] => Array
        (
            [name] => test-2.jpg
            [type] => image/jpeg
            [tmp_name] => /Applications/XAMPP/xamppfiles/temp/phpv7qFc6
            [error] => 0
            [size] => 1666451
        )

    [2] => Array
        (
            [name] => 
            [type] => 
            [tmp_name] => 
            [error] => 4
            [size] => 0
        )

    [3] => Array
        (
            [name] => 
            [type] => 
            [tmp_name] => 
            [error] => 4
            [size] => 0
        )

    [4] => Array
        (
            [name] => 
            [type] => 
            [tmp_name] => 
            [error] => 4
            [size] => 0
        )

)

---

MAIN QUESTION:

How Can I remove all of the parent array elements where the child array's [error] => 4? Thus in the example above elements [2], [3], and [4] would be deleted or unset from the array.