Request: Better failure message when token from Add a Runner page is expired

[pksublime]

Describe the bug
The error message printed by

runner/src/Runner.Listener/Configuration/ConfigurationManager.cs

Lines 848 to 851 in f9c4e17

	_term.WriteError($"Http response code: {response.StatusCode} from 'POST {githubApiUrl}' (Request Id: {githubRequestId})");
	var errorResponse = await response.Content.ReadAsStringAsync();
	_term.WriteError(errorResponse);
	response.EnsureSuccessStatusCode();

should include a hint about refreshing the Add a Runner page to get an updated token

To Reproduce
Steps to reproduce the behavior:

1. Go to the Add a Runner page in a repo
2. Wait over an hour to have the token expire
3. Try to register with the old toke and observe that you get a 404 error that doesn't really explain that the token is expired

What's not working?

--------------------------------------------------------------------------------
|        ____ _ _   _   _       _          _        _   _                      |
|       / ___(_) |_| | | |_   _| |__      / \   ___| |_(_) ___  _ __  ___      |
|      | |  _| | __| |_| | | | | '_ \    / _ \ / __| __| |/ _ \| '_ \/ __|     |
|      | |_| | | |_|  _  | |_| | |_) |  / ___ \ (__| |_| | (_) | | | \__ \     |
|       \____|_|\__|_| |_|\__,_|_.__/  /_/   \_\___|\__|_|\___/|_| |_|___/     |
|                                                                              |
|                       Self-hosted runner registration                        |
|                                                                              |
--------------------------------------------------------------------------------

# Authentication

Http response code: NotFound from 'POST https://api.github.com/actions/runner-registration' (Request Id: D444:167475:34B6912:36005D2:68C956CA)
{"message":"Not Found","documentation_url":"https://docs.github.com/rest","status":"404"}
Response status code does not indicate success: 404 (Not Found).