Unpublishes /info page prefix route

After running the migration all /info pages will return a 410.

Originally created the rake task in info-frontend [1] (where the route is
published), however the publishing-api bearer token no longer exists so
moving the tmp migration to publishing-api.

Didn't particularly trust the content-id specified in info-frontend [2]
so pulling the id from the edition in publishing-api. A manual check
shows they're both the same.

Trello:
https://trello.com/c/zODyxEf3/2372-unpublish-info-prefix-route-and-mark-as-gone

[1]: alphagov/info-frontend#1363
[2]: https://github.com/alphagov/info-frontend/blob/07e5bd441549d3ea7697584cf6d474f0f1de0674/lib/tasks/publishing_api.rake#L19

Author: 1pretz1

lib/tasks/tmp_unpublish_info_page.rake

@@ -0,0 +1,12 @@
+desc "Unpublishes /info page as part of the info-frontend retirement"
+task tmp_unpublish_info_pages: :environment do
+  info_page = Edition.live.find_by_base_path("/info")
+
+  payload = {
+    content_id: info_page.content_id,
+    type: "gone",
+    discard_drafts: true,
+  }
+
+  Commands::V2::Unpublish.call(payload)
+end