Spelling fixes to docs, docstrings, and comments (GH-6374)

(cherry picked from commit 61f82e0e337f971da57f8f513abfe693edf95aa5)

Co-authored-by: Ville Skyttä <ville.skytta@iki.fi>
diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
index af71008..de2773f 100644
--- a/Lib/test/test_strptime.py
+++ b/Lib/test/test_strptime.py
@@ -363,7 +363,7 @@
             _strptime._strptime("-01:30:30:123456", "%z")
         with self.assertRaises(ValueError) as err:
             _strptime._strptime("-01:3030", "%z")
-        self.assertEqual("Unconsistent use of : in -01:3030", str(err.exception))
+        self.assertEqual("Inconsistent use of : in -01:3030", str(err.exception))
 
     def test_timezone(self):
         # Test timezone directives.