ci: enable cancel-in-progress on concurrent run

Author: davidB

.github/workflows/ci.yml

@@ -2,11 +2,18 @@
 name: ci
 
 on:
-  push:
-    branches: [main]
   pull_request:
+  push:
+    branches:
+      - main
+      - master
+      - "releases/*"
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read