Python's experimental JIT to be removed

Python's experimental just-in-time (JIT) compiler, which was added to CPython in 2024, is being removed after the maintainers withdrew their proposal (PEP 836) to make it a supported feature. The Python steering council had requested a standards-track PEP addressing maintenance, compatibility, and success metrics, but after months of discussion, the JIT maintainers decided to withdraw their proposal, effectively ending development on the project. The decision reflects concerns about the JIT's impact on other Python initiatives like instrumentation, debugging, and profiling.