common-ostree: Replace fedora-toolbox with toolbox

The project and the command line tool were renamed. A renamed toolbox
RPM has now passed review:
https://bugzilla.redhat.com/show_bug.cgi?id=1680043

https://pagure.io/workstation-ostree-config/pull-request/130

fedora-common-ostree.json

@@ -8,7 +8,6 @@
 
     "packages": [
         "buildah",
-        "fedora-toolbox",
         "flatpak",
         "flatpak-builder",
         "git-core",
@@ -16,6 +15,7 @@
         "podman",
         "rpm-ostree",
         "skopeo",
+        "toolbox",
         "xdg-desktop-portal"
     ],