Freethreading interpreter will attempt to import unsupported stable ABI extension modules

Bug report

Bug description:

Compile a stable ABI extension module with the filename "something.abi3.so" (or .pyd on Windows)

Run python -c "import something"

A freethreading build will attempt to import the extension module, even though it explicitly isn't compatible with the stable ABI. This (unsurprisingly) leads to a crash.

Tested on beta 3.13.0b2 (but a quick search didn't find relevant changes after that)

CPython versions tested on:

3.13

Operating systems tested on:

Linux

在帶有名為 something.abi3.so 的 stable ABI 擴充功能的 freethreading CPython 3.13 建置中重現問題，然後追蹤直譯器對擴充模組匯入的處理。重新執行 python -c "import something"，並確認不會以導致當機的方式嘗試載入不受支援的 stable ABI 模組，以驗證完成的變更。