CI/Nix: include submodules

.github/workflows/nix-build.yml

@@ -18,6 +18,7 @@ jobs:
         uses: actions/checkout@v3
         with:
           ref: ${{ github.ref }}
+          submodules: 'recursive'
 
       - uses: cachix/install-nix-action@v25
       - uses: DeterminateSystems/magic-nix-cache-action@main
@@ -26,4 +27,4 @@ jobs:
           name: hyprland
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
 
-      - run: nix build .#${{ matrix.package }} -L
+      - run: nix build '.?submodules=1#${{ matrix.package }}' -L