Fix backend build

.github/workflows/docker-build-push-backend-container-on-tag.yml

@@ -8,8 +8,9 @@ on:
 jobs:
   build-and-push:
     # for EE, run on special image-builders runners
+    # TODO: make this a matrix build like the web containers
     runs-on: 
-      group: image-builders
+      group: amd64-image-builders
 
     steps:
     - name: Checkout code