Make sure uncaught exception is in last debug frame

[pdawyndt]

If an uncaught runtime exception is raised while running the Python code, the last debug frame should show that runtime error:

Now, the runtime error is shown in the penultimate debug frame, whereas nothing can be observed in the last debug frame

Source: https://dodona.be/nl/courses/3355/series/36011/activities/2055708402/

This seems behaviour that is inherited from the original Python Tutor, which even behaves worse:

Runtime error is reported in the penultimate debug frame

but this is followed by another debug frame

which is followed by yet another debug frame where the debug frame appears again

(probably reflects how runtime exception percolates through call stack)

[pdawyndt]

Version of Python Tutor in Papyros actually seems to behave exactly as the original Python Tutor (but instead of marking the extra debug frame as "Done running (?? steps)", it is not available in the debug trace.