Issue #12451: doctest.debug_script() doesn't create a temporary file anymore to
avoid encoding issues (it used the locale encoding, whereas UTF-8 should be).

Remove also an unused import (warnings).
diff --git a/Misc/NEWS b/Misc/NEWS
index 086c8da..e6c1293 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -25,6 +25,9 @@
 Library
 -------
 
+- Issue #12451: doctest.debug_script() doesn't create a temporary file
+  anymore to avoid encoding issues.
+
 - Issue #12451: pydoc.synopsis() now reads the encoding cookie if available,
   to read the Python script from the right encoding.