gh-102778: Add sys.last_exc, deprecate sys.last_type, sys.last_value,sys.last_traceback (#102779)

Lib/tkinter/__init__.py

@@ -2400,6 +2400,7 @@ class Tk(Misc, Wm):
         should when sys.stderr is None."""
         import traceback
         print("Exception in Tkinter callback", file=sys.stderr)
+        sys.last_exc = val
         sys.last_type = exc
         sys.last_value = val
         sys.last_traceback = tb