`array_split()` triggers PHP Notice when object is evaluated against integer

[AlwinGarside]

1 test triggered 1 PHP notice:

1) /Users/alwin/Projects/PHP/empaphy/usephul/src/array.php:383
Object of class stdClass could not be converted to int

Triggered by:

* Tests\Unit\array\ArraySplitTest::testSplitsAnArrayBySeparatorValue#separator: new stdclass, limit: max, strict: false
  /Users/alwin/Projects/PHP/empaphy/usephul/tests/Unit/array/ArraySplitTest.php:201