Turn off stdout/stderr redirection for vtkpython exe
By default vtkPythonInterpreter.cxx redirects all Python output to the output window, which is useful for embedded interpreters, but not for the vtkpython executable which is used from a system shell.
So we turn the redirection off in the vtkpython executable to keep the output window from stealing Python's output.
Closes: #19367
Edited by David Gobbi