build.yaml trigger on both branch and PR. Fix this with cancelling the second triggered action.

Author: havardf

.github/workflows/build.yml

@@ -5,6 +5,10 @@ on:
     branches: ["**"]
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.head.ref || github.ref_name }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build ${{ matrix.service }}