Cancel in-progress runs when pushing new code

.github/workflows/build-apple.yml

@@ -6,6 +6,9 @@ on:
   pull_request:
     branches:
     - "*"
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
 jobs:
   build:
     name: Build App (${{ matrix.platform }})