fix

.github/workflows/ci.yml

@@ -1,6 +1,7 @@
 name: "Test"
 on:
-  pull_request_target:
+  pull_request:
+    types: [opened,edited,synchronize,reopened]
   push:
     branches:
       - 'master'
@@ -12,9 +13,5 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     if: github.repository_owner == 'nix-community'
     steps:
-    - uses: actions/checkout@v3
-      with:
-        # pull_request_target checks out the base branch by default
-        ref: refs/pull/${{ github.event.pull_request.number }}/merge
     - uses: cachix/install-nix-action@v18
     - run: nix build --extra-experimental-features nix-command -L -f . -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixpkgs-unstable.tar.gz --show-trace