GIL or Global Interpreter Lock can be disabled in Python version 3.13. This is currently experimental.
Python 3.13 brings major new features compared to Python 3.12 and one of them is free-threaded mode, which disables the Global Interpreter Lock, allowing threads to run more concurrently.
The GIL will be disabled when you configure the Python with the --disable-gil option which is nothing but a build configuration (free threading build) at the time of installation.
This will allow optionally enabling and disabling GIL using the environment variable PYTHON_GIL which can be set to 1 and 0 respectively.
It will also provide a command-line option -X gil which can also be set to 0 (disable) and 1 (enable).
For multithreaded CPU-bound applications, just don’t use pure python, unless the intensive work is done in a compiled module. (Those have always been able to run without the GIL, there are a bunch of them in the standard library and other popular packages, and the API for writing custom ones is pretty good.)
C is one option for writing compiled modules, but certainly not the only one.
More importantly, writing a moderate-sized program entirely in C when only a small fraction of it needs high-performance custom behavior is likely a poor use of time, both immediately and throughout the code's life.