Cancel in-progress CI jobs for the same branch

Author: JeanChristopheMorinPerso

.github/workflows/python-package.yml

@@ -15,6 +15,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   cpp_build:
     runs-on: ${{ matrix.os }}