Source: https://gitlab.gnome.org/Teams/Design/icon-development-kit/-/blob/main/src/icons.svg
obtained using Gnome Icon Library (https://gitlab.gnome.org/World/design/icon-library)

License: CC0 1.0 Universal https://gitlab.gnome.org/Teams/Design/icon-development-kit/-/blob/main/COPYING.md

Affected files:
- challenge.png
- creative.png
- tutorial.png
- zen.png
