ci: try another nix installer

.gitea/workflows/ci.yaml

@@ -1,3 +1,5 @@
+# yaml-language-server: $schema=https://json.schemastore.org/github-workflow.json
+
 on:
   push:
     branches: 
@@ -9,8 +11,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v25
+
-        with:
+      - name: Check Nix flake inputs
-          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+        uses: DeterminateSystems/flake-checker-action@v5
+
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@main
+
       - run: nix flake check --show-trace --accept-flake-config
-# yaml-language-server: $schema=https://json.schemastore.org/github-workflow.json