ci: Setup concurrency

Author: unlight

.github/workflows/ci.yml

@@ -4,6 +4,9 @@ on:
   - pull_request
 jobs:
   build:
+    concurrency:
+      group: ${{ github.ref }}
+      cancel-in-progress: true
     name: 'Test on Node ${{ matrix.node }} and ${{ matrix.os }}'
     runs-on: '${{ matrix.os }}'
     strategy: