Update CI

Author: ale94mleon

.github/workflows/tests.yml

@@ -14,7 +14,7 @@ on:
       - setup.cfg
       - setup.py
   pull_request:
-    branches: [ "main" ]
+    types: [opened, synchronize, reopened]
     paths:
       - moldrug/**
       - .github/workflows/tests.yml
@@ -23,6 +23,10 @@ on:
       - setup.cfg
       - setup.py
 
+concurrency:
+  group: pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+  
 jobs:
   build:
     runs-on: ${{ matrix.os }}