ci: make search a seperate job

.github/workflows/update.yml

@@ -8,7 +8,7 @@ on:
     branches:
       - master
 jobs:
-  tests:
+  update_nur:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
@@ -21,6 +21,13 @@ jobs:
       run: ./ci/update-nur.sh
       env:
         API_TOKEN_GITHUB: '${{ secrets.API_TOKEN_GITHUB }}'
+  update_search:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: cachix/install-nix-action@v12
+      with:
+        nix_path: nixpkgs=channel:nixos-unstable
     - name: update nur-search/data/packages.json
       run: ./ci/update-nur-search.sh
       env: