[3.12] GH-90915: Document that SystemExit doesn't trigger sys.excepthook (GH-31357) (#109082)

GH-90915: Document that SystemExit doesn't trigger sys.excepthook (GH-31357)
(cherry picked from commit 1294fce)

Co-authored-by: Colin Watson <[email protected]>
Co-authored-by: Kumar Aditya <[email protected]>
Co-authored-by: Hugo van Kemenade <[email protected]>

Author: 4 people

Doc/library/sys.rst

@@ -378,7 +378,7 @@ always available.
 
    This function prints out a given traceback and exception to ``sys.stderr``.
 
-   When an exception is raised and uncaught, the interpreter calls
+   When an exception other than :exc:`SystemExit` is raised and uncaught, the interpreter calls
    ``sys.excepthook`` with three arguments, the exception class, exception
    instance, and a traceback object.  In an interactive session this happens just
    before control is returned to the prompt; in a Python program this happens just