Bug Description

As reported by one user in the Site Kit support forums, a depreciation notice exists, possibly from the admin toolbar. The error appears as below:

PHP Deprecated: Calling get_class() without arguments is deprecated in /.../google-site-kit/third-party/google/apiclient/src/Http/REST.php on line 49

Awaiting Site Health information from impacted user.

Note that this error was highlighted by engineering when reviewing another issue (#8589). Maybe you have some insights into this @mohitwp?

Additional Context

• PHP Version:
• OS: [e.g. iOS]
• Browser: [e.g. chrome, safari]
• Plugin Version: [e.g. 22]
• Device: [e.g. iPhone6]

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Acceptance criteria

• google/apiclient should be upgraded to 2.15.2 or higher

Implementation Brief

• Upgrade the dependency once Upgrade to Guzzle v7 #10302 is merged
• Finish and merge Upgrade apiclient #10402
  • Ensure all PHP Scoper config customization is still valid as noted in PHP Deprecated: Calling get_class() without arguments is deprecated in google-site-kit/third-party/google/apiclient/... #9977 (comment)

Test Coverage

• No changes

QA Brief

• This change updates the Google PHP packages for accessing Google APIs and using OAuth 2. Authentication and API requests to various Google services should still function.
• Perform a smoke test of the core reports on the dashboard for various Site Kit modules (Search Console, Analytics, etc.) and test across different supported PHP and WordPress versions.

Changelog entry

• Upgrade Google API client library to avoid deprecation notices on latest versions of PHP.