Performance improvement to add schema caching to pattern and menu item REST endpoints, so identical schema object are not needlessly regenerated. Props spacedmonkey. Fixes #58657. See [45811]. Built from https://develop.svn.wordpress.org/trunk@56093 git-svn-id: http://core.svn.wordpress.org/trunk@55605 1a063a9b-81f0-0310-95a4-ce76da25c4cd