[Tracking] Dark mode

[julien-deramond]

This issue tracks dark mode reverts we'll need to do when the dark mode will be implemented:

• Check modifications in Reintroduce all text color utilities #2030 (most of the one linked to the text colors must be reverted)
  • 214f1d0
  • 8b46e1f
  • TODO: add others
• Docs: Add real thumbnail img #2034 (review)
• Think to modify 983d0eb if needed
• Revisit this Bootstrap section (https://getbootstrap.com/docs/5.3/components/navbar/#color-schemes) in Boosted which is hidden for now but could work when we'll get rid of .navbar-dark and replace it with data-bs-theme="dark"