python2Packages: remove superfluous overrides

Since Python 2 is not supported anymore we only keep those overrides
which are used by leaf packages.

pkgs/development/python-modules/oauthlib/3.1.nix

@@ -1,33 +0,0 @@
-{ lib
-, buildPythonPackage
-, fetchPypi
-, mock
-, pytest
-, cryptography
-, blinker
-, pyjwt
-}:
-
-buildPythonPackage rec {
-  pname = "oauthlib";
-  version = "3.1.0";
-
-  src = fetchPypi {
-    inherit pname version;
-    sha256 = "bee41cc35fcca6e988463cacc3bcb8a96224f470ca547e697b604cc697b2f889";
-  };
-
-  checkInputs = [ mock pytest ];
-  propagatedBuildInputs = [ cryptography blinker pyjwt ];
-
-  checkPhase = ''
-    py.test tests/
-  '';
-
-  meta = with lib; {
-    homepage = "https://github.com/idan/oauthlib";
-    description = "A generic, spec-compliant, thorough implementation of the OAuth request-signing logic";
-    maintainers = with maintainers; [ prikhi ];
-    license = licenses.bsd3;
-  };
-}