Update build.yml

Author: BFergerson

.github/workflows/build.yml

@@ -15,8 +15,10 @@ on:
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
+    concurrency:
+      group: ${{ github.workflow }}-${{ github.ref }}
+      cancel-in-progress: true
 
     steps:
     - uses: actions/checkout@v2