bpo-41634: Fix a typo in the curses documentation (GH-21958)

(cherry picked from commit 398575c)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Doc/library/curses.rst

@@ -708,7 +708,7 @@ the following methods and attributes:
             window.addch(y, x, ch[, attr])
 
    Paint character *ch* at ``(y, x)`` with attributes *attr*, overwriting any
-   character previously painter at that location.  By default, the character
+   character previously painted at that location.  By default, the character
    position and attributes are the current settings for the window object.
 
    .. note::