fix(normal): don't check conceal when pressing 'r' (#27892)

Problem:  Cursor line is unconcealed when pressing 'r' in Normal mode
          when 'concealcursor' contains 'n' but not 'i'.
Solution: Don't check conceal when pressing 'r' in Normal mode.

Vim doesn't have this problem because it doesn't call redrawWinline() in
conceal_check_cursor_line() and instead sets a global variable.

src/nvim/normal.c

@@ -748,7 +748,7 @@ static void normal_get_additional_char(NormalState *s)
     bool langmap_active = false;  // using :lmap mappings
     if (repl) {
       State = MODE_REPLACE;                // pretend Replace mode
-      ui_cursor_shape();              // show different cursor shape
+      ui_cursor_shape_no_check_conceal();  // show different cursor shape
     }
     if (lang && curbuf->b_p_iminsert == B_IMODE_LMAP) {
       // Allow mappings defined with ":lmap".