Themes: Add unlink-homepage-logo to the create_initial_theme_features()...

Themes: Add unlink-homepage-logo to the create_initial_theme_features() registration for the custom-logo theme feature.
Follow-up to [48039], [48283], [48749], [48757], [48758].

This brings the changes to the 5.5 branch.

Props TimothyBlynJacobs, SergeyBiryukov, whyisjake.
Fixes #37011.

Built from https://develop.svn.wordpress.org/branches/5.5@48759


git-svn-id: https://core.svn.wordpress.org/branches/5.5@48521 1a063a9b-81f0-0310-95a4-ce76da25c4cd