Remove last usage of six Python 2 compatibility layer (#3033)

see https://wiki.debian.org/Python3-six-removal

parsl/app/errors.py

@@ -6,8 +6,6 @@
 import logging
 from tblib import Traceback
 
-from six import reraise
-
 from parsl.data_provider.files import File
 from parsl.errors import ParslError
 
@@ -109,8 +107,6 @@ def __init__(self, e_type: type, e_value: BaseException, traceback: Optional[Tra
 
     def reraise(self) -> None:
 
-        t = self.e_type
-
         # the type is logged here before deserialising v and tb
         # because occasionally there are problems deserialising the
         # value (see #785, #548) and the fix is related to the
@@ -119,7 +115,7 @@ def reraise(self) -> None:
 
         v = self.get_exception()
 
-        reraise(t, v, v.__traceback__)
+        raise v
 
     def get_exception(self) -> BaseException:
         v = self.e_value

requirements.txt

@@ -1,7 +1,6 @@
 pyzmq>=17.1.2
 typeguard>=2.10,<3
 typing-extensions>=4.6,<5
-six
 globus-sdk
 dill
 tblib

test-requirements.txt

@@ -10,7 +10,6 @@ sphinx_rtd_theme
 mypy==1.5.1
 types-python-dateutil
 types-requests
-types-six
 types-paramiko
 mpi4py