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

在带有名为 something.abi3.so 的 stable ABI 扩展的 freethreading CPython 3.13 构建中重现该问题，然后跟踪解释器对扩展模块导入的处理。重新运行 python -c "import something"，并确认不会以导致崩溃的方式尝试加载不受支持的 stable ABI 模块，以验证完成的更改。