Bug fixes

This release addresses the following issues, most notably adding better support for keyboard accessibility:

Note: This release includes a fix for a regression involving the theme hook suggestion name for blocks (the twig template names). If your site provides twig template overrides for blocks based on the selected layout builder style, be sure to test they're still working correctly after updating. They are now correctly based on the "machine name" of the layout builder style.

All issues in this release:

add placeholder and fix notices for php 7.4

Stable realease.
Minor bugfix.

Resolves issues with optimistic locking and prevents the triggering of handlers when a post is performed.

Fix notice from php 7.4