[META] alpha8 release issues (8.x-1.0-alpha8)

A collection of tasks for alpha8 release.

Remaining tasks

• In Progress
• Planned
• Done
  • #3078119: Add support for navbar toggle close button
  • #3078120: Decouple support for navbar off-canvas and dropdown menus from basic navigation support
  • #3073818: New $disabled-color SASS variable for easier controlling of disabled components color
  • #3073813: Make fieldset twig template easier to extend by adding block definitions inside of it
  • #3073433: Fieldset legend should not be rendered when it is empty
  • #3071854: Generated child themes no longer consider theme-options.yml
  • #3072589: When using the language code option for language switcher active language label is not changed
  • #3071132: Browserslist: caniuse-lite is outdated, check and update other libraries also
  • #3071001: When creating a new theme version information from parent themes are missing
  • #3071003: Allow theme naming with only alpha-numeric characters and underscore
• Backlog
  • #3012575: Add/port layout support for sticky navbar and absolute header options
  • #3008293: Remove custom jasny bootstrap offcanvas solution and use BS5 offcanvas component
  • #2844385: Default button.css file is too big
  • #2870726: Fluid type and spacing scale (opt-in in 2.1, default in 3.0)
  • #2882696: [META] Support for admin forms/pages
  • #2883247: Improve dropdown button/link support
  • #2899894: Investigate moving main form action buttons to sidebar
  • #2883831: Support for icons for mime types is missing
  • #2896011: Figure what to do with background and sizing utilities
  • #2874049: Add sub-option in gulp options to toggle deepmerge option inheritance
  • #3047339: Introduce bootstrap's spinner as throbber