Fix syntax error in struct doc example (GH-102160)

Missing closing ) reported on Discuss by Chukwudi Nwachukwu.
(cherry picked from commit 8f64747)

Co-authored-by: Terry Jan Reedy <[email protected]>

Author: miss-islington

Doc/library/struct.rst

@@ -371,7 +371,7 @@ ordering::
     >>> from struct import *
     >>> pack(">bhl", 1, 2, 3)
     b'\x01\x00\x02\x00\x00\x00\x03'
-    >>> unpack('>bhl', b'\x01\x00\x02\x00\x00\x00\x03'
+    >>> unpack('>bhl', b'\x01\x00\x02\x00\x00\x00\x03')
     (1, 2, 3)
     >>> calcsize('>bhl')
     7