Convert all remaining json manifests to yaml

This conversion can be validated using this script:

 #!/bin/bash

mkdir -p repo && cd repo && ostree init --repo . --mode=archive && cd ..
variants=('silverblue' 'kinoite' 'xfce' 'lxqt')

for v in ${variants[@]}; do
    sudo rpm-ostree compose tree --repo=repo --print-only fedora-$v.yaml > $v.yaml.out
done

git checkout --quiet HEAD~
for v in ${variants[@]}; do
    sudo rpm-ostree compose tree --repo=repo --print-only fedora-$v.yaml > $v.json.out
done

for v in ${variants[@]}; do
    if [[ ! -z $(diff $v.json.out $v.yaml.out) ]]; then
        echo ""
        echo "$v: JSON != YAML"
        diff $v.json.out $v.yaml.out
        echo ""
        has_diff="true"
    fi
done

git checkout --quiet master
rm -rf ./repo
for v in ${variants[@]}; do
    rm ./$v.json.out ./$v.yaml.out
done

if [[ $has_diff == "true" ]]; then
    echo "Found some diff!"
else
    echo "OK!"
fi

fedora-lxqt.yaml

@@ -1,4 +1,4 @@
-include: lxqt-desktop-pkgs.json
+include: lxqt-desktop-pkgs.yaml
 ref: fedora/rawhide/${basearch}/lxqt
 rojig:
   name: fedora-lxqt
@@ -6,6 +6,7 @@ rojig:
   license: MIT
 packages:
   - libqtxdg
+  # Portals for Flatpak
   - xdg-desktop-portal-kde
 
 repos: