AO3-6893 Patch departure the right way to prevent lock issues

[brianjaustin]

Pull Request Checklist

Issue

https://otwarchive.atlassian.net/browse/AO3-6893

Purpose

I did this the wrong way in in #5068 , and testing did not hit the right parts to trigger the original bug. This pulls from the linked issue directly to fix things. (Good news, I think this means the upstream fix will be pretty simple... hopefully)

[brianjaustin]

Testing output from staging

ao3app@test-app16:~/app/current$ rails db:migrate:down VERSION=20250129101817
Including for_alter statements
== 20250129101817 RemoveNotNullOnActiveStorageBlobsChecksum: reverting ========
-- change_column_null(:active_storage_blobs, :checksum, false, nil)
   -> 0.2643s
== 20250129101817 RemoveNotNullOnActiveStorageBlobsChecksum: reverted (0.2687s) 

ao3app@test-app16:~/app/current$ rails db:migrate:up VERSION=20250129101817
Including for_alter statements
== 20250129101817 RemoveNotNullOnActiveStorageBlobsChecksum: migrating ========
-- table_exists?(:active_storage_blobs)
   -> 0.0018s
-- change_column_null(:active_storage_blobs, :checksum, true, nil)
   -> 0.2555s
== 20250129101817 RemoveNotNullOnActiveStorageBlobsChecksum: migrated (0.2574s) 

[redsummernight]

Is this still needed?

[redsummernight]

Never mind, I see your commit message now. This is to fully reverse the patch at https://github.com/departurerb/departure/blob/982966c8e57a1cb0c3a1c0083cc3d3d0b74da51d/lib/departure/connection_base.rb.