Add Node.js install for lint and pre-install Flatpak SDK

.forgejo/workflows/pr-checks.yml

@@ -10,6 +10,8 @@ jobs:
     container:
       image: swift:6.3
     steps:
+      - name: Install Node.js
+        run: apt-get update -qq && apt-get install -y -qq nodejs
       - uses: actions/checkout@v4
       - name: Lint
         run: swift format lint --recursive Sources/
@@ -21,6 +23,10 @@ jobs:
       options: --privileged
     steps:
       - uses: actions/checkout@v4
+      - name: Pre-install Flatpak SDK
+        run: |
+          flatpak remote-add --user --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
+          flatpak install --user --noninteractive org.gnome.Platform//50 org.gnome.Sdk//50 2>&1 | tail -5
       - uses: https://github.com/flatpak/flatpak-github-actions/flatpak-builder@v6.7
         with:
           manifest-path: dev.bscubed.Luminate.json