feat: Update Stan to 2.39.0, bump version

Update Stan to 2.39.0, bump httpstan version.

Author: Your Name

Makefile

@@ -11,9 +11,9 @@
 
 PYBIND11_VERSION := 2.9.2
 RAPIDJSON_VERSION := 1.1.0
-STAN_VERSION := 2.38.0
-STANC_VERSION := 2.38.0
-MATH_VERSION := 5.2.0
+STAN_VERSION := 2.39.0
+STANC_VERSION := 2.39.0
+MATH_VERSION := 5.3.0
 # NOTE: boost, eigen, sundials, and tbb versions must match those found in Stan Math
 BOOST_VERSION := 1.87.0
 EIGEN_VERSION := 3.4.0

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "httpstan"
-version = "4.16.0"
+version = "4.17.0"
 description = "HTTP-based interface to Stan, a package for Bayesian inference."
 authors = [
   "Allen Riddell <riddella@indiana.edu>",