Compile adiabatic sweep with `build_function`

[oameye]

The current implementation of the adiabatic sweep problem does not compile harmonic equations. It would be more performant to do this with build_function.

https://github.com/NonlinearOscillations/HarmonicBalance.jl/blob/6bd32de04a2d0523125a38a50d0108711f6ca215/ext/TimeEvolution/ODEProblem.jl#L33-L49