SiwG throws error on WP 6.0.3 and below

[mohitwp]

Bug Description

I tested SIWG functionality across different WordPress versions and noticed that the SIWG module throws a fatal error on WordPress 6.0.3 and earlier versions. Additionally, the SIWG option and block do not appear on the front end even after connecting SIWG

Fatal error: Uncaught Error: Call to undefined function Google\Site_Kit\Modules\is_login() in /.../wp-content/plugins/google-site-kit/includes/Modules/Sign_In_With_Google.php:391 Stack trace:
#0 /.../wp-content/plugins/google-site-kit/includes/Core/Util/Method_Proxy_Trait.php(25): Google\Site_Kit\Modules\Sign_In_With_Google->render_signinwithgoogle()
#1 /.../wp-includes/class-wp-hook.php(307): Google\Site_Kit\Modules\Sign_In_With_Google->Google\Site_Kit\Core\Util\{closure}()
#2 /.../wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters()
#3 /.../wp-includes/plugin.php(476): WP_Hook->do_action()
#4 /.../wp-login in /.../wp-content/plugins/google-site-kit/includes/Modules/Sign_In_With_Google.php on line 391

Steps to reproduce

1. Create a site using WordPress version 6.0.3 or earlier.
2. Set up Site Kit.
3. Connect the SIWG module.
4. Open the WordPress admin panel or the front end of the site in a different browser or an incognito tab.

Screenshots

Additional Context

• WP Version - 6.0.3 or earlier

---

Do not alter or remove anything below. The following sections will be managed by moderators only.

Acceptance criteria

• No errors should be raised when SiwG is connected on all supported versions of WP

Implementation Brief

• Inline usage of is_login with its simple implementation from core https://github.com/WordPress/wordpress-develop/blob/6.7/src/wp-includes/load.php#L1307-L1309

Test Coverage

• No changes expected

QA Brief

Changelog entry