[df] Ruff changes in test file

Author: vepadulano

roottest/python/distrdf/backends/test_all.py

@@ -1,26 +1,24 @@
+import shlex
 import sys
 
 import pytest
-
 from check_backend import *
 from check_cloned_actions import *
-from check_distribute_cppcode import * 
 from check_definepersample import *
-from check_fromspec import *
+from check_distribute_cppcode import *
+from check_distribute_headers_sharedlibs_files import *
 from check_explicit_api import *
-from check_friend_trees_alignment import *
 from check_friend_trees import *
+from check_friend_trees_alignment import *
+from check_fromspec import *
 from check_histo_write import *
-from check_distribute_headers_sharedlibs_files import *
 from check_inv_mass import *
 from check_live_visualize import *
 from check_missing_values import *
 from check_reducer_merge import *
 from check_rungraphs import *
 from check_variations import *
 
-import shlex
-
 if __name__ == "__main__":
     # The call to sys.exit is needed otherwise CTest would just ignore the
     # results returned by pytest, even in case of errors.