Update workflow to run on push to master

.github/workflows/flake.yml

@@ -1,23 +1,17 @@
-name: Flake8
-on:
-  workflow_dispatch:
-  schedule:
-    - cron: "0 1 * * *" # 3 AM CET
-  push:
-  pull_request:
+concurrency:
+  cancel-in-progress: true
+  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
 jobs:
   flake8:
     uses: steinwurf/flake8-action/.github/workflows/action.yml@2.0.0
     with:
       excluded_errors: F632
-
-
-
-
-
-
-
-# Cancel previous in-progress when pushing: https://stackoverflow.com/a/72408109
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
-  cancel-in-progress: true
+name: Flake8
+'on':
+  pull_request: null
+  push:
+    branches:
+    - master
+  schedule:
+  - cron: 0 1 * * *
+  workflow_dispatch: null