Run `ConvertConditionToIfOps` at all optimisation levels

[jakelishman]

When using the dynamic-circuits pipelines (well, if anybody still is), there's a catch to only insert ConvertConditionsToIfOps if the optimisation level was 0 or 1, because at Qiskit's initial support (way back in qiskit-terra 0.22 or something), those were the only supported optimisation levels. The story long since changed about that (though realistically, I doubt anybody was using .c_if with the dynamic-circuits paths, given how attentive you had to be to the particulars of the documentation anyway).