Fix Implicitly marking parameter $maxItems as nullable is deprecated

[bytestream]

PHP Deprecated:  PhrozenByte\PHPUnitArrayAsserts\ArrayAssertsTrait::assertSequentialArray(): Implicitly marking parameter $maxItems as nullable is deprecated, the explicit nullable type must be used instead in /vendor/phrozenbyte/phpunit-array-asserts/src/ArrayAssertsTrait.php on line 158
PHP Deprecated:  PhrozenByte\PHPUnitArrayAsserts\ArrayAssertsTrait::sequentialArray(): Implicitly marking parameter $maxItems as nullable is deprecated, the explicit nullable type must be used instead in /vendor/phrozenbyte/phpunit-array-asserts/src/ArrayAssertsTrait.php on line 186

[PhrozenByte]

Thanks! ❤️

I just additionally updated the CI to check up to PHP 8.4 and fixed the same deprecation notices in the test suite. Unfortunately the same deprecations also affect Psalm 4 which therefore doesn't work with PHP 8.4. So, no static code analysis for PHP 8.4… 😒 See #2 for details. Help is very welcome (like any other PR, too, btw).

I just pushed a new tag for both phpunit-array-asserts and phpunit-throwable-asserts. Please go ahead and report any issues 👍 Fun fact: Since I tagged your squashed commit GitHub shows that you tagged that release 😄