Solver speedup meta issue

This is a meta issue to track sub issues relating to different ways in which we can increase the speed of solving coupled ODEs in ModularCirc.

From some initial profiling I've looked at, most time is likely taken up by the `solve_ivp` step which is a scipy algorithm for solving the "initial value problem" of ODEs. If a better/faster solver can be found, this might speedup the whole process.

Alternatively, @MaxBalmus was mentioning there is likely a list comprehension bottleneck. I think he was referring to lines inside the `advance_cycle()` function in `Solver.py`. How the dataframe gets updated with new values after each cycle might be inefficient.