Trying out matrix strategy

.github/workflows/maintenance.yml

@@ -1,6 +1,6 @@
 # This is a basic workflow to help you get started with Actions
 
-name: CI
+name: Runner maintenance
 
 # Controls when the workflow will run
 on:
@@ -11,20 +11,28 @@ on:
 jobs:
   # This workflow contains a single job called "build"
   build:
+    strategy:
+      matrix:
+        runner:
+          - mac-1
+          - mac-2
+          - mac-3
+          - mac-4
     # The type of runner that the job will run on
-    runs-on: [self-hosted, docker]
+    runs-on: 
+      - self-hosted
+      - ${{ matrix.runner }}
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - uses: actions/checkout@v4
 
-      # Runs a single command using the runners shell
-      - name: Run a one-line script
-        run: echo Hello, world!
-
       # Runs a set of commands using the runners shell
-      - name: Run a multi-line script
+      - name: Docker cleanup
+        run: |
+          docker system prune -fa
+      - name: Runner upgrades
         run: |
-          echo Add other actions to build,
-          echo test, and deploy your project.
+          omz update
+          brew upgrade