add max parallel to 1

Author: pcriadoperez

.github/workflows/python-app.yml

@@ -36,6 +36,7 @@ jobs:
     runs-on: ubuntu-22.04
     timeout-minutes: 40
     strategy:
+      max-parallel: 1
       matrix:
         python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
     env: