Do not block ps:exec when stack is container

Hello Herokai friends!

I ran into a client side case where, when using Heroku Private Spaces with Docker containers, we are unable to use ps:exec without adding the heroku/exec buildpack.

𝝙 heroku stack:set container -a $APP
𝝙 heroku ps:exec
▸   $APP has no Buildpack URL set. You must deploy your
▸   application first!

𝝙 heroku buildpacks:add heroku/exec -a $APP
buildpack added. Next release on $APP will use heroku/exec.
Run git push heroku main to create a new release using this buildpack.

𝝙 heroku ps:exec -a $APP
Establishing credentials... done
[... further proof of success]

I know it's a use case is not officially supported but I suspect blocking the connection is an oversight and not intentional.

heroku / heroku-exec-util

Do not block ps:exec when stack is container #31