feat: implement effortless RPM removal via YAML configuration

You can now easily remove RPMs from your custom image, without having to edit the build.sh script.

This also changes the old "rpms" config key, to "rpm-install", for consistency with the new setting.

recipe.yml

@@ -30,10 +30,17 @@ extrarepos:
   # example:
   # - https://copr.fedorainfracloud.org/coprs/atim/starship/repo/fedora-38/atim-starship-fedora-38.repo
 
+# These RPMs will be removed from the system image. This step happens during
+# image build, before installing custom RPMs (from the "rpm-install" category).
+rpm-remove:
+  # Remove the native firefox (from Fedora) in favor of the Flatpak.
+  - firefox
+  - firefox-langpacks
+
 # These RPMs will be installed from your enabled repositories (Fedora's own repos,
 # any "extrarepos" you've added, etc). The installation is automatically performed
 # via rpm-ostree during the image build, and will be pre-installed in the final image.
-rpms:
+rpm-install:
   # Needed for yafti (the first boot installer). Remove if you're not using yafti.
   - python3-pip
   # GNOME's GTK4 Theme, Libadwaita. It already comes with silverblue, but not other spins.