CI: use DetSys Nix installer

.github/workflows/editorconfig.yml

@@ -8,14 +8,14 @@ on:
 jobs:
   check-editorconfig:
     runs-on: ubuntu-latest
-    if: "!contains(github.event.pull_request.title, '[skip treewide]')"
+    if: "!contains(github.event.pull_request.title, '[skip ci]')"
     steps:
       - name: Get list of changed files from PR
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           gh api \
-            repos/NixOS/nixpkgs/pulls/${{github.event.number}}/files --paginate \
+            repos/notashelf/neovim-flake/pulls/${{github.event.number}}/files --paginate \
             | jq '.[] | select(.status != "removed") | .filename' \
             > "$HOME/changed_files"
 
@@ -29,15 +29,12 @@ jobs:
           ref: refs/pull/${{ github.event.pull_request.number }}/merge
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v23
+        uses: DeterminateSystems/nix-installer-action@main
-        with:
+      - uses: DeterminateSystems/magic-nix-cache-action@main
-          # nixpkgs commit is pinned so that it doesn't break
-          # editorconfig-checker 2.4.0
-          nix_path: nixpkgs=https://github.com/NixOS/nixpkgs/archive/c473cc8714710179df205b153f4e9fa007107ff9.tar.gz
 
       - name: Checking EditorConfig
         run: |
-          cat "$HOME/changed_files" | nix-shell -p editorconfig-checker --run 'xargs -r editorconfig-checker -disable-indent-size'
+          cat "$HOME/changed_files" | nix-shell -p editorconfig-checker.out --run 'xargs -r editorconfig-checker -disable-indent-size'
 
       - if: ${{ failure() }}
         shell: bash