[3.12] Fix grammar typo in `Doc/c-api/arg.rst` (GH-130741) (#130758)

Fix grammar typo in `Doc/c-api/arg.rst` (GH-130741)
(cherry picked from commit 37145cb89fe806377a5e9ed1fdac92dd3a5df2c0)

Co-authored-by: Arijit Kumar Das <arijitkrdas2004@outlook.com>

diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst
index 76a197bbec73e4e01d109f92eb21348390d526bd..9d53d0e56a4e7590a3789ba09ce1828a9c7a6986 100644 (file)
--- a/Doc/c-api/arg.rst
+++ b/Doc/c-api/arg.rst
@@ -5,7 +5,7 @@
 Parsing arguments and building values
 =====================================
 
-These functions are useful when creating your own extensions functions and
+These functions are useful when creating your own extension functions and
 methods.  Additional information and examples are available in
 :ref:`extending-index`.