Ruby 3.3 Rails 3.1.3

[jasonfine]

Some notable things:

1. The highlight color test is flickering, I've noted my findings at the top of /spec/features/highlight_spec.rb. Spent some time wheel spinning on fixes for it but nothing seems to be a workable solution. It seems to be related to the database_cleaner removing records in the middle of the test. I've confirmed the functionality in the tests is fully working in the dummy app.
2. Removed the datadog connection since we aren't really using that anymore.
3. Locked Carrierwave to 2.2.6. 3.x is introducing weird file renaming behavior when cloning attachments. Cloned attachments should be keeping their original filename, 3.x is adding a _2_.ext to the duplicated filename.