feat: use policy-based error handling in interpolators

[fpelliccioni]

This PR updates cubic_hermite, makima, and pchip interpolators to use boost::math::policies::raise_domain_error instead of throwing exceptions.
This aligns their error handling with Boost.Math’s policy-based approach.

Related PR

#1244 depends on this PR.

Summary

Replaces exceptions with policy-based error handling.
Ensures compatibility with compile-time tests where exceptions are disabled.

Next Steps

Once merged, #1244 will be unblocked and ready for review.

[mborland]

I'm not a fan of changing the API to add policy support unless you have a compelling reason. I think this could simply have replaced the current throw std::whatever to using the boost policy for signaling errors.

I feel like this is un-ergonomic:

   auto ret = boost::math::interpolators::pchip<std::vector<double>>::create(std::move(data_x), std::move(data_y), 3, 2);
   check_result<double>(ret.first->operator()(1.0));

compared to:

boost::math::interpolators::pchip<std::vector<double>> s(std::move(data_x), std::move(data_y), 3, 2);
   check_result<double>(s(1.0));

CC: @NAThompson

[mborland]

I like this a lot more than the first iteration.

[mborland]

LGTM now. I kicked off the CI run to make sure it agrees.