ncurses 6.4 - patch 20230708

+ add linux+kbs for terminals which imitate xterm's behavior with
  Linux -TD
+ modify MinGW driver to return KEY_BACKSPACE when an unmodified
  VK_BACK virtual key is entered (prompted by patch by Pavel Fedin,
  Savannah #64292).
+ disallow using $TERMINFO or $HOME/.terminfo when tic "-o" option is
  used (report by Sven Joachim, Debian #1040048).