Add missing @return tags for WP_Automatic_Updater methods

[ankitmaru]

Missing @return tag in function/method PHPDoc comment

[mukesh27]

Hi there!

Thanks for the patch. Can you please add send_core_update_notification_email() function return type and other function which miss the return type?

[ankitmaru]

@mukesh27 I have updated the file added the missing return statements.

Thanks.

[mukesh27]

Thanks for the patch

[SergeyBiryukov]

In 49061:

Docs: Add missing @return tags for some WP_Automatic_Updater methods:

• ::is_vcs_checkout()
• ::should_update()
• ::send_core_update_notification_email()

Props ankitmaru, mukesh27.
Fixes #51385.