feat: Automattic#2392: add arm based ubuntu runner

Author: dsdeboer

.github/workflows/prebuild.yaml

@@ -51,9 +51,10 @@ jobs:
       fail-fast: false
       matrix:
         node: [21]
+        os: ["ubuntu-latest", "ubuntu-latest-arm"]
         canvas_tag: ["v3.1.0"] # e.g. "v2.6.1"
     name: ${{ matrix.canvas_tag }}, Node.js ${{ matrix.node }}, Linux
-    runs-on: ubuntu-latest
+    runs-on: matrix.os
     container:
       image: ${{ matrix.node < 18 && 'chearon/canvas-prebuilt:9' || 'zbbjornson/canvas-prebuilt:11' }}
     env: