2026-09-07: Remove code to support Python 2.7, Python 3.5 and PyPy
for Python 2.7 ("pypy2").
Python 2.7 was no longer supported since August 2023.
Python 3.5 was no longer supported since October 2024.
2022-02-11: The project license changes from the MIT license to the Zero
Clause BSD (0BSD) license. Projects copying pythoncapi_compat.h no longer
have to include the MIT license and the copyright notice.
2022-02-08: Add documentation.
2022-02-09: pythoncapi_compat.h now supports C++ on Python 3.6 and newer:
use nullptr and reinterpret_cast<type> cast on C++, and use NULL
and (type) cast on C.
2021-10-15: Add PyThreadState_EnterTracing() and
PyThreadState_LeaveTracing().