Fix problems causing fatal errors in the recent release. (#38114)

* Added safeguards against null body class.

* Changelog.

* Infinite Scroll: added safeguards against non-initialized Sharing module.

* Changelog.

* Fix fatals when attributes are not an array.

* Project versions.

* Update projects/plugins/jetpack/modules/infinite-scroll/infinity.php

Co-authored-by: Brad Jorsch <anomiex@users.noreply.github.com>

* Remove unneeded precautions.

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Co-authored-by: Brad Jorsch <anomiex@users.noreply.github.com>

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/9717240714

Upstream-Ref: Automattic/jetpack@affec6d