PythonInfo.from_exe() reports Python 3.9 for a Python 3.13 executable

[dimbleby]

On Amazon Linux 2023, PythonInfo.from_exe() resolves a copied Python 3.13 venv to the system-default Python 3.9.

Reproducer

FROM public.ecr.aws/amazonlinux/amazonlinux:2023@sha256:5d271dd33b628252c31c15f5449e50d7c4e9f93badf9342f9b1e2a8d326fbe84

RUN dnf install -y python3.13 python3.13-pip
RUN python3.13 -m venv --copies /venv \
    && /venv/bin/pip install python-discovery==1.4.2

RUN /venv/bin/python - <<'PY'
import subprocess
import sys
from python_discovery import PythonInfo

info = PythonInfo.from_exe(sys.executable)
print(subprocess.check_output([sys.executable, "--version"], text=True).strip())
print(f"{info.executable=}")
print(f"{info.system_executable=}")
print(f"{info.version_info=}")
PY

docker build --no-cache --progress=plain .
Output:

Python 3.13.14
info.executable='/venv/bin/python'
info.system_executable='/usr/bin/python3'
info.version_info=VersionInfo(major=3, minor=9, micro=25, ...)

/usr/bin/python3 points to Python 3.9, while this venv was created from /usr/bin/python3.13.

It appears _fast_get_system_executable() trusts the existing sys._base_executable (/usr/bin/python3) without checking that its version matches the interpreter being inspected. I would expect system_executable to be /usr/bin/python3.13 and version_info to report 3.13.