Python's `sys.executable` points to Julia's binary on Windows

When Python's `sys` module is loaded via `pyimport("sys")` its `executable` returns Julia's path instead of Python's. The same doesn't happen on Linux.

To reproduce this issue (Windows 10, Julia 1.7.0, PyCall 1.93.0):
```
julia> using PyCall

julia> sys = pyimport("sys")
PyObject

julia> sys.executable
"C:\\Users\\User\\AppData\\Local\\Programs\\Julia-1.7.0\\bin\\julia.exe"
```