gh-98790: When DLLs directory is missing on Windows, assume executable_dir contains PYD files instead

[zooba]

• Issue: Embedded Python 3.11 on windows warns about <exec_prefix> #98790

[FFY00]

As I mentioned in #98790 (comment), I think trying to make the behavior closer to what it used to be is the right approach for now, so I am in favor of this fix 👍

[zooba]

We're quite a way away from the old behaviour, which was basically a hard-coded (incorrect) default. What I just pushed is going to handle the missing DLLs directory case best, but by omitting the path and shifting the actual one up in the order. Previously, there'd be references to the missing directories, which isn't great, so I fixed that up.

Also dropped the search on Windows, which we never used to do and is just as unsafe on Windows as it is anywhere else.

[miss-islington]

Thanks @zooba for the PR 🌮🎉.. I'm working now to backport this PR to: 3.11.
🐍🍒⛏🤖

[miss-islington]

Sorry, @zooba, I could not cleanly backport this to 3.11 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 3d889dc0a0efa6fcbd984ece365c9ac08d2cd4a9 3.11

[bedevere-bot]

GH-99019 is a backport of this pull request to the 3.11 branch.

[gpshead]

This appears to have caused a regression in 3.11.1 forcing some people to stick with 3.11.0: #100171