Fix PHP 8.4 deprecations

[v-noskov]

Implicitly marking function/method parameters as nullable is deprecated in PHP 8.4. Please, fix deprecation at least in these classes:

docusign/esign-client/src/Client/ApiClient.php:91
DocuSign\eSign\Client\ApiClient::__construct(): Implicitly marking parameter $config as nullable is deprecated, the explicit nullable type must be used instead
DocuSign\eSign\Client\ApiClient::__construct(): Implicitly marking parameter $oAuth as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Configuration.php:185
DocuSign\eSign\Configuration::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/EnvelopeDefinition.php:626
DocuSign\eSign\Model\EnvelopeDefinition::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/EnvelopeSummary.php:216
DocuSign\eSign\Model\EnvelopeSummary::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/EnvelopeTemplateResults.php:216
DocuSign\eSign\Model\EnvelopeTemplateResults::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/RecipientViewRequest.php:261
DocuSign\eSign\Model\RecipientViewRequest::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/Tabs.php:371
DocuSign\eSign\Model\Tabs::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/TemplateRole.php:256
DocuSign\eSign\Model\TemplateRole::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/Text.php:776
DocuSign\eSign\Model\Text::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead

docusign/esign-client/src/Model/ViewUrl.php:180
DocuSign\eSign\Model\ViewUrl::__construct(): Implicitly marking parameter $data as nullable is deprecated, the explicit nullable type must be used instead