Athib/fix deprecated warning

[athib]

Adding return types on SensioLabs\Insight\Sdk\Model\Violations to fix the deprecated notices on analysis

Deprecated: Return type of SensioLabs\Insight\Sdk\Model\Violations::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in phar:///usr/bin/insight/Sdk/Model/Violations.php on line 25
Deprecated: Return type of SensioLabs\Insight\Sdk\Model\Violations::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in phar:///usr/bin/insight/Sdk/Model/Violations.php on line 30

[nicolas-grekas]

Thank you.