Schemathesis error logs are enormous again

[leafty]

See example: https://github.com/SwissDataScienceCenter/renku-data-services/actions/runs/12315443903/job/34373892498?pr=545

Avoid repr for large objects not relevant to tests in the Case class.

[Stranger6667]

Hey, Schemathesis author here. I see you use 3.29.2 - FYI, newer versions have those fields hidden (3.38.10 should have the relevant changes). In Schemathesis v4, I plan to make it even cleaner. Hopefully, upgrading will resolve the issue.