Update dependencies

[jamescurtin]

As part of drafting a different PR, I ran pip-compile and noticed that it resulted in some packages being upgraded.

1. The first commit is the auto-generated change resulting from re-running pip-compile ./requirements.in.
2. Upgrading Django resulted in the auto-generation of some login-related frontend code, which is committed in the second commit.
3. One package, easy-thumbnails, had an incompatibility with Django 5.1 (documented here), which is resolved in the third commit by setting a minimum version for the package as well as explicitly setting the storage backend.

While I have confirmed that the app starts up successfully, I do not yet have a more robust testing strategy for making changes like this--in particular given that the Django upgrade was across a major version. I figured I'd start by proposing this change in the spirit of keeping dependences up-to-date--but if this seems risky given the current light test coverage, I can re-work this and just pin django<5 in requirements.in.

[iragm]

Awesome work. I do not want to merge this one just yet, I am about to go out of town for a couple days and don't want to break things right before I leave. I will test stuff and merge it next week.