Log Message:
nlopt: updated to 2.9.1

NLopt 2.9.1

* Fixed PRAXIS box constraints

NLopt 2.9

* New `NLOPT_LUKSAN` cmake option to build without Luksan LGPL code

* Dropped unused LD_LBFGS_NOCEDAL enum value.

* Python 3.13 support

* Fixed COBYLA not returning the optimum

* Fixed SLSQP returning infeasible optimum

* Fixed STOGO not registering new optimum

* Various minor bugfixes

NLopt 2.8

* Support C++ functors for objective functions

* CCSA/MMA an now use the `initial_step` parameter to bound their initial stepsize,
  and also expose a new internal parameter `rho_init`

* Install `pkg-config` file on Windows

* Allow having more equality constraints than there are variables

* Bugfixes to `nlopt_algorithm_name`