Disabled test: Investigate root cause.

[sjunges]

There is one parametric test that fails and is currently disabled for that reason.

Note that the test also fails for me on macOS 26. The comments mentions it being successful for Ubuntu 22.04 which we do not support anymore. Maybe the test actually hints at an issue which should be fixed?

Originally posted by @volkm in #990 (comment)

[tquatmann]

This is the test.

I had another test in that file failing in #1049. That was due to slightly different double-results on the original vs. transformed model. I switched all calculations in that test to exact which apparently also resolved this issue (or there was an independent flaw in the bisimulation code that is now fixed).