In order to test WordPress/gutenberg#41786 and preparing for when that one gets merged we should implement link hover (and probably focus?) styles on our themes. I think we should start with:

• Blockbase Blockbase: move link pseudo states to theme.json #6156
• Blank canvas
• Block Canvas Block canvas: replacing button :hover CSS by theme.json definition #6486
• Curator Vivre: move link pseudo states to theme.json #6150
• Livro
• Skatepark
• Stewart
• Pendant Pendant: replacing CSS with theme.json settings for link elements #6179

And follow up to clean up CSS from any other themes that are using it.

There's a PR for Archeo already open.