fix(ui): correct condition for "wrap" flag in a floating grid

In a floating window grid, "wrap" flag should not
be set when vertical borders are used, as the the wrapped
text will be broken up by border chars.

fixes #33719

test/functional/ui/screen.lua

@@ -1230,12 +1230,13 @@ end
 --- @param row integer
 --- @param col integer
 --- @param items integer[][]
-function Screen:_handle_grid_line(grid, row, col, items)
+function Screen:_handle_grid_line(grid, row, col, items, wrap)
   assert(self._options.ext_linegrid)
   assert(#items > 0)
   local line = self._grids[grid].rows[row + 1]
   local colpos = col + 1
   local hl_id = 0
+  line.wrap = wrap
   for _, item in ipairs(items) do
     local text, hl_id_cell, count = item[1], item[2], item[3]
     if hl_id_cell ~= nil then