ci: run publish workflow on ubuntu instead of macos

The macos runner might be busy and the workflow might not run in time.

.github/workflows/publish.yml

@@ -7,7 +7,9 @@ on:
 jobs:
   pr-pull:
     if: contains(github.event.pull_request.labels.*.name, 'Automerge')
-    runs-on: macos-14
+    runs-on: ubuntu-22.04
+    container:
+      image: ghcr.io/homebrew/ubuntu22.04:master
     permissions:
       actions: read
       pull-requests: write