[FEATURE] Implement automated test data solution

Is your feature request related to a problem? Please describe.
#58 was marked as "Done" because the investigation is complete, but we still need to meet, decide, and implement a test data solution. There's also an outstanding pull request with one proposed approach (#66 ). So, this task involved:

• Review the work in #58 and #66
• Meet and decide on solution
• Implement the solution

Describe the solution you'd like
I'm partial to that implemented in #66 , but as identified there, we have these remaining questions/tasks even if we decide to adopt that PR as is:

• Add documentation on how to record/re-record cassettes to this repo's wiki
• Determine whether or not we need to create a "source of truth" db and/or API collection in order to bootstrap bulk re-recording tests no matter the developer (in theory, this isn't necessary, but it might be a nice-to-have)
• Investigating whether everything currently in requirements.txt needs to be there (it's being called in CI now, so we may want to just generally keep aware of what's in and what's not in there)
• Consider caching in CI if we do want to keep all those dependencies available
• Document how we'll adopt this moving forward. This PR only updates one specific test. Do we want to also take a bit of time now to update others, or only address them as we need to on an ad hoc basis when changes or features are added?

Describe alternatives you've considered
Documented in #58

Additional context
Getting this task on our board so we don't forget it and so that #66 doesn't continue to age. But this isn't super high priority.

Start by reviewing the investigation in #58 and the proposed approach in #66, including its cassette workflow and the test it updates. Resolve the open questions about requirements.txt, CI caching, a source-of-truth database or API collection, and rollout scope. Done means a chosen solution is implemented, cassette re-recording and adoption are documented in the wiki, and the relevant tests and CI workflow work.