why isn't linux running

Author: chearon

.github/workflows/prebuild.yaml

@@ -54,7 +54,7 @@ jobs:
         canvas_tag: ["v3.1.1"] # e.g. "v2.6.1"
         os: ["ubuntu-latest", "ubuntu-latest-arm"]
     name: ${{ matrix.canvas_tag }}, Node.js ${{ matrix.node }}, Linux
-    runs-on: matrix.os
+    runs-on: ${{ matrix.os }}
     container:
       image: ${{ matrix.os == 'ubuntu-latest-arm' && 'chearon/canvas-prebuilt-arm:1' || 'zbbjornson/canvas-prebuilt:11' }}
     env: