GTK+4 is available
GNOME 3.24 has become the first GNOME version to be released along a GTK+4 build, version 3.90.0. Either the GTK+3 NSIS scripts should be upgraded or a new package has to be made.
For this to happen, first a package will need to be added for Gtk+4 to MSYS2's MINGW packages as I (no longer) build the Gtk stacks myself. Feel free to submit one there and I will consider pull requests that add a Gtk+4 NSIS script.
This being said, I wonder if it's not too soon to go ahead with this as the API is not guaranteed to be stable until 4.0.0 will be released, which I am not sure will happen even this year.
gtk 4 package was added https://packages.msys2.org/package/mingw-w64-x86_64-gtk4?repo=mingw64
I will look it at some point but I won't be doing this soon as I have no personal need for it. Feel free to open a PR.