Defining an alternate s3 configuration set to `public: true` means we can use it selectively. It sets the objects to `acl: "public-read"` by default (read-only) and means any image tags for those assets can use direct public links in the src attribute (without hitting the ActiveStorage::Representation endpoint). The default non-public service will still be used by default for any other files on instances using s3.
We were also patching ActiveRecord::Relation for the `#find_by_param`
methods but we are not using those any more. They were deprecated a
while ago. We now use `find_by(permalink: ...)`.
