[$] Getting extensions to work with free-threaded Python

One of the biggest changes to come to the Python world is the addition of the free-threadinginterpreter, which eliminates the globalinterpreter lock (GIL) that kept the interpreter thread-safe, but alsoserialized multi-threaded Python code. Over the years, the GIL has been asource of complaints about the scalability of Python code usingthreads, so many developers have been looking forward to the change, whichhas been an experimental feature since Python 3.13was released in October 2024. Making the free-threaded version workwith the rest of the Python ecosystem, especially native extensions, is anongoing effort, however; Nathan Goldbaum and Lysandros Nikolaou spoke at PyCon US 2025 about those efforts.