Rational: gtk2 is not maintained anymore and the change was simple.
- Update of nativefiledialog/CMakeLists.txt in order to detect and use
gtk3
- Updated a few files referencing gtk2, especially:
- github workflow: I tested that the apt-get update works on ubuntu
18.03 in a docker container
- Readme.
This was tested in the following nixpkgs PR: https://github.com/NixOS/nixpkgs/pull/107878
f30addc70d