Doc: Fix missing bracket (GH-13163)

diff --git a/Doc/distutils/setupscript.rst b/Doc/distutils/setupscript.rst
index 54ed1ae..a65a26a 100644
--- a/Doc/distutils/setupscript.rst
+++ b/Doc/distutils/setupscript.rst
@@ -523,7 +523,7 @@
 
     setup(...,
           data_files=[('bitmaps', ['bm/b1.gif', 'bm/b2.gif']),
-                      ('config', ['cfg/data.cfg']),
+                      ('config', ['cfg/data.cfg'])],
          )
 
 Each (*directory*, *files*) pair in the sequence specifies the installation