ENH: Remove python interface introspection

The generation of the pyhton interface from
basic introspection was insufficient for
meaningfully improving IDE experiences.

Remove this implementation in favor of
creating a separate itk-stubs repository
with manually enhanced python interface files.

Wrapping/Generators/Python/CMakeLists.txt

@@ -150,7 +150,6 @@ if(NOT EXTERNAL_WRAP_ITK_PROJECT)
     itk/support/itkInitHelpers
     itk/support/itkBuildOptions
     itk/__init__
-    itk_generate_pyi # A utility function used to generate the intreface file
     )
   # Done listing files.
   # Now copy these files if necessary.
@@ -998,10 +997,3 @@ else()
   endmacro()
 
 endif()
-
-add_custom_command(OUTPUT ${ITK_WRAP_PYTHON_ROOT_BINARY_DIR}/itk/__init__.pyi
-    COMMAND ${Python3_EXECUTABLE} ${ITK_WRAP_PYTHON_ROOT_BINARY_DIR}/itk_generate_pyi.py
-    DEPENDS ${ITK_WRAP_PYTHON_FILES} ${WRAPPER_LIBRARY_NAME}Swig
-    WORKING_DIRECTORY ${ITK_WRAP_PYTHON_ROOT_BINARY_DIR}
-    COMMENT "Building python type interface file itk/__init__.pyi for the itk package"
-)