Windows CI built app problems

One small problem with the Windows CI is that %HOME% is empty, resulting in the app building at `/pyapp` which is also odd as it should be a Windows path not a Unix path.

But more interesting is that the Built App job log doesnt emit that always-important "hello, world" . e.g. https://dev.azure.com/gregoryszorc/PyOxidizer/_build/results?buildId=233&view=logs ends with

```console
packaging application into D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug
copying D:/pyapp\build\target\x86_64-pc-windows-msvc\debug\pyapp.exe to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\pyapp.exe
resolving packaging state...
writing license for _bz2 to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.bzip2.txt
writing license for _ctypes to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.libffi.txt
writing license for _hashlib to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.openssl.txt
writing license for _lzma to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.liblzma.txt
writing license for _sqlite3 to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.sqlite.txt
writing license for _ssl to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.openssl.txt
writing license for python to D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug\LICENSE.python.txt
pyapp packaged into D:/pyapp\build\apps\pyapp\x86_64-pc-windows-msvc\debug
##[section]Finishing: Build Oxidized Application (Windows)
```

Start with the Windows CI Built App job and its build log, especially the empty %HOME% value, the /pyapp path, and the missing "hello, world" output. Reproduce the Windows build and verify that the app uses a Windows path and emits the expected output after packaging.

Written by the indexing model from the issue text.