enforce new flake schema. formatting.

templates/dev/flask-hello/.github/workflows/python-nix.yml

@@ -1,23 +1,20 @@
+---
 name: Python Nix Pipeline
 
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    branches: [ master ]
+on:  # yamllint disable-line
 
 jobs:
   build-and-test:
     name: Build and Test
     runs-on: ubuntu-latest
-    
+
     steps:
-    - uses: actions/checkout@v3
-    
-    - name: Set up Nix
-      uses: cachix/install-nix-action@v18
-      with:
+      - uses: actions/checkout@v3
+
+      - name: Set up Nix
+        uses: cachix/install-nix-action@v18
+        with:
           nix_path: nixpkgs=channel:nixos-unstable
 
-    - name: Run nix flake check
-      run: nix flake check
+      - name: Run nix flake check
+        run: nix flake check