Fix for window very-long-filename support. NFC

[sbc100]

We have a function called fix_potentially_long_windows_pathname which is used when unzipping archives under windows.

Without this the unzip process will fail if the total filename length ever exceeds 256. This change adds a test for installing deep in the filesystem (where pathnames exceed 256) and fixes a bug in this code which was causing the test to fail.

The fact that this code had this bug for god-known-how-long means I think nobody was depending on it, so we could probably just remove it, but maybe better to fix it and add this test?

[sbc100]

I verified that with the fix_potentially_long_windows_pathname calls this new test fails with:

Unzipping file 'C:/Users/circleci/project/very_long_filename_indeedxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/downloads/node-v22.16.0-win-x64.zip' failed due to reason: [Errno 2] No such file or directory: 'C:\\Users\\circleci\\project\\very_long_filename_indeedxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\\node\\unzip_temp\\node-v22.16.0-win-x64\\bin\\node_modules\\npm\\node_modules\\qrcode-terminal\\vendor\\QRCode\\QRErrorCorrectLevel.js'