fix CI runs

.github/workflows/vulnix.yml

@@ -11,18 +11,13 @@ permissions:
 
 jobs:
   scan:
-    runs-on: ubuntu-latest
+    runs-on: nix
     steps:
       - uses: actions/checkout@v4
 
-      - uses: cachix/install-nix-action@v31
-        with:
-          extra_nix_config: |
-            experimental-features = nix-command flakes
-
       - name: scan host closures
         id: scan
-        run: echo "count=$(nix run .#ci -- vulnix . "$RUNNER_TEMP/issue.md")" >> "$GITHUB_OUTPUT"
+        run: echo "count=$(nix run -L .#ci -- vulnix . "$RUNNER_TEMP/issue.md")" >> "$GITHUB_OUTPUT"
 
       - name: file/update issue
         if: steps.scan.outputs.count != '0'
@@ -30,7 +25,7 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           API: ${{ github.api_url }}
           REPO: ${{ github.repository }}
-        run: nix run .#ci -- upsert-issue vulnix "vulnix: known vulnerabilities in system closure" "$RUNNER_TEMP/issue.md"
+        run: nix run -L .#ci -- upsert-issue vulnix "vulnix: known vulnerabilities in system closure" "$RUNNER_TEMP/issue.md"
 
       - name: close resolved issue
         if: steps.scan.outputs.count == '0'
@@ -38,4 +33,4 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           API: ${{ github.api_url }}
           REPO: ${{ github.repository }}
-        run: nix run .#ci -- close-issue vulnix
+        run: nix run -L .#ci -- close-issue vulnix