Remove argparse module (#263)

argparse has been part of the standard library since Python 3.2 and has
been [archived](https://pypi.org/project/argparse/) on PyPI. Nothing
uses the copy in `//third_party/python` any more, so remove it.

Author: chrisnovakovic

third_party/python/BUILD

@@ -395,12 +395,6 @@ pip_library(
     version = "8.2.1",
 )
 
-pip_library(
-    name = "argparse",
-    licences = ["PSF-2.0"],
-    version = "1.4.0",
-)
-
 pip_library(
     name = "distlib",
     licences = ["PSF-2.0"],