run updater natively (#394)

see Fediversity/Fediversity#65 (comment).

closes #65.

Reviewed-on: Fediversity/Fediversity#394
Co-authored-by: Kiara Grouwstra <kiara@procolix.eu>
Co-committed-by: Kiara Grouwstra <kiara@procolix.eu>

.forgejo/workflows/update.yaml

@@ -7,15 +7,16 @@ on:
 
 jobs:
   lockfile:
-    runs-on: ubuntu-latest
+    runs-on: native
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
-      - name: Install Nix
-        uses: cachix/install-nix-action@v31
       - name: Install npins
-        run: nix profile install 'nixpkgs#npins'
-      - name: Update npins sources
-        uses: getchoo/update-npins@v0
+        run: nix-shell --run "npins update"
+      - name: Create PR
+        uses: peter-evans/create-pull-request@v7
         with:
           token: "${{ secrets.DEPLOY_KEY }}"
+          branch: npins-update
+          commit-message: "npins: update sources"
+          title: "npins: update sources"