python-app: update workflow

.github/workflows/python-app.yml

@@ -6,29 +6,29 @@ name: Python application
 on:
   push:
     branches: [ '**' ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ "master" ]
 
 jobs:
   build:
     runs-on: ${{ matrix.os }}
 
     strategy:
       matrix:
-        python-version: [ 3.7, 3.8, 3.9, "3.10", "3.11" ]
+        python-version: [ 3.8, 3.9, "3.10", "3.11" ]
         os: [ ubuntu-latest, macos-latest, windows-latest ]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Lint with flake8
         run: |
           python -m pip install flake8
-          # stop the build if there are Python syntax errors or undefined names
-          flake8 . --count --select=E9,F63,F7,F82,F401,E741 --show-source --statistics
-          # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-          flake8 . --count --exit-zero --max-complexity=14 --max-line-length=127 --statistics
+          flake8 . --max-line-length=127
       - name: Verify sorted imports
         run: |
           python -m pip install isort