cleanup: remove unnecessary option restore_win_options

This was only necessary to begin with because I was using `vim.wo` to
set window options. I mistakenly thought that would set the option as
window-local, but it did not. This was fixed in
6f8bf067c0. Now all the window options
should function as expected without the extra logic.

lua/oil/init.lua

@@ -719,7 +719,6 @@ M.save = function(opts)
 end
 
 local function restore_alt_buf()
-  local config = require("oil.config")
   if vim.bo.filetype == "oil" then
     require("oil.view").set_win_options()
     vim.api.nvim_win_set_var(0, "oil_did_enter", true)
@@ -742,10 +741,6 @@ local function restore_alt_buf()
         end
       end
     end
-
-    if config.restore_win_options then
-      require("oil.view").restore_win_options()
-    end
   end
 end