The add_*_script methods now accept a File as the first argument

Meson now accepts file objects, including those produced by configure_file as the prog (first) parameter of the various add_*_script methods

install_script = configure_file(
  configuration : conf,
  input : 'myscript.py.in',
  output : 'myscript.py',
)

meson.add_install_script(install_script, other, params)