Explicitly mark parameters as nullable

[agibson-godaddy]

Summary

Replacement for #784

This updates method signatures to explicitly mark parameters as nullable, where previously they were implicitly declared as such. This addresses deprecation warnings in PHP 8.4+.

Story: MWC-18270

Release: #787(release PR)

Details

Additional details to expand on the summary, if needed

QA

• Code review

Before merge

• I have confirmed these changes in each supported minor WooCommerce version

[Copilot]

Pull Request Overview

This PR addresses PHP 8.4+ deprecation warnings by explicitly marking nullable parameters in method signatures throughout the WooCommerce payment gateway framework. PHP 8.4 deprecated the implicit nullable parameter syntax and now requires explicit ? notation for nullable parameters.

• Updates method signatures to use explicit nullable syntax (?Type instead of Type = null)
• Adds corresponding PHPDoc updates to reflect nullable parameter types
• Updates changelog to document the PHP 8.4 compatibility improvement

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
class-sv-wc-payment-gateway-payment-tokens-handler.php	Updates get_token_by_core_id method to explicitly mark $environment_id as nullable
class-sv-wc-payment-gateway.php	Updates credit card charge and authorization methods to explicitly mark $order parameters as nullable
class-sv-wc-payment-gateway-my-payment-methods.php	Updates get_payment_method_default_html method to explicitly mark $token parameter as nullable
class-sv-wc-payment-gateway-direct.php	Updates do_add_payment_method_transaction method to explicitly mark $response parameter as nullable
Abstract_Payment_Handler.php	Updates multiple order processing methods to explicitly mark response parameters as nullable
Abstract_Hosted_Payment_Handler.php	Updates transaction response handling methods to explicitly mark order and response parameters as nullable
changelog.txt	Documents the PHP 8.4 compatibility improvement

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