feat(edit)!: remove old c implementation of hebrew keymap

This feature has long been obsolete. The 'keymap' option can be used
to support language keymaps, including hebrew and hebrewp (phonetic
mapping). There is no need to keep the old c code with hardcoded
keymaps for some languages.

src/nvim/screen.c

@@ -534,9 +534,6 @@ int showmode(void)
         } else if (restart_edit == 'V') {
           msg_puts_attr(_(" (vreplace)"), attr);
         }
-        if (p_hkmap) {
-          msg_puts_attr(_(" Hebrew"), attr);
-        }
         if (State & MODE_LANGMAP) {
           if (curwin->w_p_arab) {
             msg_puts_attr(_(" Arabic"), attr);