Test container build

I want this to kick off the build action and successfully build, but I expect
that it will fail on the push because it's in my own fork and doesn't have the
needed permissions.

.github/workflows/publish-container.yml

@@ -7,6 +7,7 @@ on:
       - v[0-9]+.[0-9]+.[0-9]+
     branches:
       - main
+      - pull_181
   repository_dispatch:
     types:
       - dispatch-build