Fix long path issue on Windows

[radoering]

Path.is_relative_to() does not work if one of both paths has a long path prefix and the other has not. A long path prefix may be added when calling Path.resolve().

Originally, the issue was noticed in Poetry's CI. (Poetry applies the same check as installer.)
With additional debug output, the error looked like:

[68](https://github.com/radoering/poetry/actions/runs/23705665774/job/69057056580#step:5:6069)
E           Attempting to write py.test.exe outside of the target directory
E           Target directory: C:\Users\runneradmin\AppData\Local\Temp\pytest-of-runneradmin\pytest-0\popen-gw0\test_execute_prints_warning_fo1\.venv\scripts
E           Target path: \\?\C:\Users\runneradmin\AppData\Local\Temp\pytest-of-runneradmin\pytest-0\popen-gw0\test_execute_prints_warning_fo1\.venv\scripts\py.test.exe

Related Poetry PR: python-poetry/poetry#10794

[Secrus]

Thank you for your contribution