20.0-RC7

Changes compared to: 20.0-RC6

Non user facing:

• Improves accessibility for mobile navigation by changing style of menu open and close button, and the default screen reader text of that component. #19604
• Fixes an unreleased issue where the post types were no longer keyed by post type name. This had a number of consequences: Media showed up under Content types, Breadcrumbs for post types, Post type schema defaults, the Media pages page and the categories & tags page descriptions should say which post type they fall under. #19640
• Adds focus to radio buttons with inline-block variant. #19633
• Increases the contrast of the Settings toggles. #19608