Consider using InterpreterPoolExecutor

[akhmerov]

After reading https://docs.python.org/3.14/whatsnew/3.14.html#pep-734-multiple-interpreters-in-the-standard-library I wonder if we should detect whether we're using python >= 3.14 and if that is the case make InterpreterPoolExecutor the default, rather than ProcessPoolExecutor.

[akhmerov]

Blocked by e.g. numpy/numpy#24755