ci: set concurrency rule to stop outdated running tasks

Author: artus9033

.github/workflows/ci.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [main]
 
+concurrency:
+  group: pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   build-lint:
     name: Build & static code analysis