language/python: setup_install_args

Add a helper like std_cmake_args that returns the correct incantation
for invoking setup.py in a consistent way and with our preferred
arguments. Replaces setup_install.
Formula#system: hide python setup.py shim in ohai
Formula#exec_cmd: recognize setuptools shim and refurbish args
Language::Python.setup_install: add deprecation warning
use Language::Python.setup_install_args instead of setup_install
docs: recommend setup_install_args instead of setup_install

Closes #34793.
translate-toolkit: update 1.12.0 bottle.