Add PEP 741 PyInitConfig API to the limited C API

The GDB project would be interested to use the limited C API to embed Python. Some APIs used by GDB are missing from the limited C API (well, it's limited ;-)), one of them is the PEP 741 PyInitConfig API.

I propose adding PEP 741 PyInitConfig API to the limited C API.

PEP 741 Rationale lists other projects embedding Python. More projects would benefit from PyInitConfig being in the limited C API.

For example, the vim text editor uses dlopen/dlsym and GetProcAddress on Windows to get Python symbols at runtime. The libpython library is loaded on demand (at the first Python usage). vim already supports the stable ABI. See src/if_python3.c.

So far, I found pyinstaller which already adopted the PyInitConfig API.

Linked PRs

• gh-149194

PEP 741 の埋め込みに関する根拠を読み、Vim の src/if_python3.c を調べて limited ABI のユースケースを理解してください。次に、リンクされた PR gh-149194 と limited C API に関する作業を確認してください。PyInitConfig がこの API を通じて Python を埋め込むプロジェクトで利用可能になれば完了です。