This includes the following PRs

• Generate babel polyfill dynamically Babel Preset Default: Add polyfill for WordPress built from core-js gutenberg#31279
• Improve the List View component List View: Simplify the BlockNavigation component gutenberg#31290 Block Navigation: try using CSS for indentation with known max indent instead of spacer divs gutenberg#32063
• Template mode:
  • Fix embed dimensions Iframed editor: fix embed dimensions with missing wp-embed-responsive class gutenberg#32057
  • Update the welcome guide Update the graphic that appears in the Template Editor welcome guide gutenberg#32055 Update Welcome Guides to use external image URLs gutenberg#32026
  • Don’t display the notice at the same time as the welcome guide Template Mode: Don't display snackbar with the Welcome Guide gutenberg#32076
  • Remove MetaBoxes Remove metaboxes from template mode gutenberg#32315
  • Update the title area Update the title area in the template editor gutenberg#32037
• Widgets Screen:
  • Fix unsaved changes Widget Screen: Fix unsaved changes notification gutenberg#31757
  • Fix toolbar alignment Fix toolbar alignment in widget block editor gutenberg#31991
  • Fix block toolbar position after scroll Widgets editor: fix block toolbar position after scroll gutenberg#32212
  • Fix the visible widget area header Fix the visible widget area toolbar gutenberg#32262
  • Fix legacy widgets preview Fix legacy widget previews gutenberg#32260
• Block Widgets in the customizer:
  • Fix customizer title overlapping block toolbar Fix issue with customizer title overlapping block toolbar gutenberg#32140
  • Fix styling issues Fix some smaller styling issues and bugs in Widgets Customizer gutenberg#32072
  • Fix escape key events Fix escape key events in customizer closing the editor gutenberg#32175
  • Add preferences menu group label Add preferences menu group label to widgets and customize widget editor gutenberg#32259
  • Fix creating and replacing legacy widgets Fix creating and replacing legacy widgets in customizer gutenberg#32005
  • Fix the welcome guide’s image Center the welcome image in narrow viewport of widgets customizer gutenberg#32264 Fix aspect ratio of welcome image gutenberg#32302
• Fix Cover to Image transform duotone error Fix image/cover transform duotone error gutenberg#32006
• Remove filter_var usage from blocks Remove filter_var from blocks gutenberg#32046
• Fix image width for aligned Post Featured Image block Fix image width for wide aligned Post featured image gutenberg#32070
• Prevent excessive Image block re-rendering Image block: fix cover transform and excessive re-rendering gutenberg#32102
• Remove gutenberg domain from core blocks Remove gutenberg domain from core blocks gutenberg#32152
• Use the block editor context class for the the different settings filters Plugin: Update block editor settings to work with context gutenberg#32159
• Fix Latest Posts block grid view Latest Posts: Declare 'hasPosts' before 'inspectorControls' gutenberg#32160
• Fix preset classes generation per block Fix generation of presets classes per block gutenberg#32190
• Fix logic to enable custom colors and gradients Fix: Logic to enable custom colors, gradients, and font sizes. gutenberg#32200
• Update the Site Logo logic to use a dedicated site option site-logo block: Use option instead of theme-mod gutenberg#32229
• Limit the Latest Posts block’s featured image width Limit latest posts featured image width to 100% gutenberg#32245
• Remove opacity animation in the canvas. Try: Remove opacity animation on canvas. gutenberg#32266
• Make the focus style valid CSS Try: Make focus style valid CSS. gutenberg#32305
• Fix theme.json styles for the core/list block Fix theme.json styles for the core/list block gutenberg#32343
• Fix PHP notice when calling render_block Avoid a PHP Notice when render_block() is called without attributes. gutenberg#32135

The PHP changes are not backported yet, we need to check this diff:

WordPress/gutenberg@51adf3d...wp/trunk

https://core.trac.wordpress.org/ticket/52991

PHP backports required:

• Update elements block supports.
• Theme.json presets classes changes and unit test.
• Fix for enabling custom colors and gradients.
• Enable and backport the site logo block (can be done separately)
• Potentially use the new generated polyfill (can be done separately)