Support pyenv on Windows

[nre-ableton]

This PR adds support for Windows in pyenv.createVirtualEnv(). I've bumped the minor version since this is technically a breaking change, as these functions previously resulted in an error being thrown when run on Windows.

[nre-ableton]

@ala-ableton my changes should squash cleanly. Let me know when I should squash.

[ala-ableton]

Please fix 31ed1db and we're almost done.

[ala-ableton]

In 43d3b35, we now have export PATH=... twice.

[nre-ableton]

In 43d3b35, we now have export PATH=... twice.

Sorry about that. Fixed in b5b1c96.

[ala-ableton]

Please rebase/squash, then re-rebase and edit 43d3b35 to make sure that export PYENV_ROOT=... keeps on coming before export PATH=..., instead of having export PATH=... move around.

[nre-ableton]

So I've rebased this PR, and also added Windows support for the newly-added integration tests, but they keep timing out after 1 hour.

The first time, the build failed with a different error (not a timeout):

[2022-07-28T08:33:57.000Z] F:/jenkins-node/workspace@tmp/durable-6cb19c97/script.sh: line 4: /f/jenkins-node/workspace/.venv/venv-95957963/Scripts/activate: No such file or directory

I've no idea why this is happening. 😞

[nre-ableton]

@ala-ableton I've rebased this PR, ptal!

[ala-ableton]

Please rebase on the latest main state and drop the following commits:

• 4b31949
• 9943386
• ab8dc4d

[nre-ableton]

I've rebased and edited the history as requested, but there are some failing tests that I will investigate next week. I will re-request a review once these have been fixed.

[nre-ableton]

@ala-ableton I fixed the issues with the tests, but I think that a preparation PR would be better for all the non-Windows-specific stuff. So I've opened up #164, which I assume you'll be interested in reviewing.

[ala-ableton]

Please apply changes similar to a4c566d to Windows-specific tests.

[nre-ableton]

@ala-ableton I’m ok with your fixup, so I’ll go ahead and squash

[nre-ableton]

@ablbot autosquash

[ableton-ablbot]

Rebase job dfe5d703-6e82-417a-874b-6c2bd6cb89c0 has been created. There are currently 0 job(s) in the queue.

_{This message was generated by ablbot. For help: use @ablbot help, see @ablbot's documentation, or the Ableton CI Guide.}

[ableton-ablbot]

Rebase of nre/master/2497-pyenv-windows onto main has succeeded.

_{This message was generated by ablbot. For help: use @ablbot help, see @ablbot's documentation, or the Ableton CI Guide.}

[ala-ableton]

LGTM 👍🏻