Rethink vcr tapes
We currently have more than 110 tapes and when merge requests rerecord tapes we can get a diff of more than 100 files. The GitLab ui takes ages to load such a diff online, and it's not really ideal to check offline either...
I wonder if we can switch to a system where gitlab ci creates the tapes and publishes them somewhere so people who want to run the tests locally can grab them.
Or get rid of the tapes altogether and use a containerized version of mailman-core to run the tests.
Devs would have to install docker on their machines. Although docker images for a production setup of core are not easy, tests don't actually require sending emails, so the issues all go away.
An additional benefit of not using tapes would be that we are independent of how the tapes are recorded. Currently the tapes depend on what environment is used. (we don't enforce anything, and I'm not sure how this would be checked). Negative side effects of this can currently be observed in mailmanclient!10 (closed) and would probably also surface here once python3.x support is added to Postorius. (Making this issue affect all the projects that rely on vcr_tapes for testing)
What do you think?