Update build.yml

Author: staabm

.github/workflows/build.yml

@@ -8,6 +8,10 @@ on:
     branches:
       - "2.0.x"
 
+concurrency:
+  group: build-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
+  cancel-in-progress: true
+
 jobs:
   lint:
     name: "Lint"