ci: automatically cancel previous jobs on new commits

.github/workflows/images-debian.yml

@@ -7,6 +7,10 @@ on:
       - 'tools/qemu-debian-img/**'
       - '.github/workflows/images-debian.yml'
 
+concurrency:
+  group: ${{ github.workflow_ref }}
+  cancel-in-progress: true
+
 jobs:
   images:
     name: Qemu Images

.github/workflows/images-oraclelinux.yml

@@ -7,6 +7,10 @@ on:
       - 'tools/qemu-oraclelinux-img/**'
       - '.github/workflows/images-oraclelinux.yml'
 
+concurrency:
+  group: ${{ github.workflow_ref }}
+  cancel-in-progress: true
+
 jobs:
   images-oraclelinux:
     name: Qemu Images

.github/workflows/macos.yml

@@ -11,6 +11,10 @@ on:
       - "README.md"
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow_ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build

.github/workflows/ubuntu.yml

@@ -11,6 +11,10 @@ on:
       - "README.md"
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow_ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build