Fix punctuation in `os.execvpe` docstring. (GH-15051)

(cherry picked from commit fb6807b043ab586428225920373e551b0432bc40)

Co-authored-by: Hasan Ramezani <hasan.r67@gmail.com>
diff --git a/Lib/os.py b/Lib/os.py
index 79ff7a2..2009025 100644
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -568,7 +568,7 @@
     """execvpe(file, args, env)
 
     Execute the executable file (which is searched for along $PATH)
-    with argument list args and environment env , replacing the
+    with argument list args and environment env, replacing the
     current process.
     args may be a list or tuple of strings. """
     _execvpe(file, args, env)