ENV.shared: deprecate ncurses_define

This was only used by 2 formuale in homebrew-core.
One formula did not need the flag anymore and the flag was removed
The other formula (rogue) still needs it, the flag was directly
added to the formula.

There is no reason for us to keep this method.

Library/Homebrew/extend/ENV/shared.rb

@@ -241,6 +241,8 @@ module SharedEnvExtension
   # Currently only used by aalib in core.
   sig { void }
   def ncurses_define
+    # odeprecated "ENV.ncurses_define"
+
     append "CPPFLAGS", "-DNCURSES_OPAQUE=0"
   end