Remove deprecation notice on nullable properties in method signatures

[LaurentBrieu]

Description

Update methods signatures to avoid deprecation notices when using PHP 8.4 :

Brevo\Client\Api\EventsApi::__construct(): Implicitly marking parameter $client as nullable is deprecated, the explicit nullable type must be used instead in lib/Api/EventsApi.php on line 72
Brevo\Client\Api\EventsApi::__construct(): Implicitly marking parameter $config as nullable is deprecated, the explicit nullable type must be used instead in lib/Api/EventsApi.php on line 72
Brevo\Client\Api\EventsApi::__construct(): Implicitly marking parameter $selector as nullable is deprecated, the explicit nullable type must be used instead in lib/Api/EventsApi.php on line 72

Proposed Solution

Generally speaking, across the whole project, it will be cool to set the expected types in method signatures, so that we don't have that kind of deprecations in the future.

Regarding the ones i've mentionned above, here's a quick fix in lib/Api/EventsApi.php.

public function __construct(
        ?ClientInterface $client = null,
        ?Configuration $config = null,
        ?HeaderSelector $selector = null
) {

Disclaimer

This fix will not be suitable for users that uses PHP < 7.1.

When does the support of PHP 5.6/7.0 will stop ?

[Soben]

Noting that I'm also encountering this with PHP 8.4, with the CreateSmtpEmail construct

Deprecated: Brevo\Client\Model\CreateSmtpEmail::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead in /var/www/html/vendor/getbrevo/brevo-php/lib/Model/CreateSmtpEmail.php on line 183