[3.13] gh-123925: Fix building curses on platforms without libncursesw (GH-128405) (GH-128407)

(cherry picked from commit 8d16919)

Co-authored-by: Serhiy Storchaka <[email protected]>

Author: miss-islington

Misc/NEWS.d/next/Build/2025-01-02-11-02-45.gh-issue-123925.TLlyUi.rst

@@ -0,0 +1,2 @@
+Fix building the :mod:`curses` module on platforms with libncurses but
+without libncursesw.

Modules/_cursesmodule.c

@@ -137,7 +137,7 @@ typedef chtype attr_t;           /* No attr_t type is available */
 #define STRICT_SYSV_CURSES
 #endif
 
-#if NCURSES_EXT_FUNCS+0 >= 20170401 && NCURSES_EXT_COLORS+0 >= 20170401
+#if defined(HAVE_NCURSESW) && NCURSES_EXT_FUNCS+0 >= 20170401 && NCURSES_EXT_COLORS+0 >= 20170401
 #define _NCURSES_EXTENDED_COLOR_FUNCS   1
 #else
 #define _NCURSES_EXTENDED_COLOR_FUNCS   0