Fix Spring framework test to detect failure better

[nickelization]

As visible here: https://buildkite.com/readyset/readyset/builds/29449#0188c04f-31f6-4ca7-a7ae-7b60bdaed041 it is possible for the test to encounter errors and yet still appear to pass in CI. More investigation needed to determine exactly what's going on here.

_{From SyncLinear.com | REA-2904}