Remove long obsolete unsafe interrupt exception (#8139)

Remove long obsolete unsafe interrupt exception (#8139)

We used to use UnsafeInterruptException to deal with resource outs in the resource manager: when resources were exhausted, we would throw this exception that was catched in the core solver engine. This had the significant downside of leaving the solver in a potentially inconsistent state. We moved away from using it long ago in #4732.
What remained was the UnsafeInterruptException class itself and a bunch of places that still catch this exception that is no longer thrown anywhere.

This PR removes this class for good.