GHSA-v2wf-c3j6-wpvw

### Impact The use of `Plug.Session` in `Pow.Plug.Session` is susceptible to session fixation attacks if a persistent session store is used for `Plug.Session`, such as Redis or a database. Cookie store, which is used in most Phoenix apps, doesn't have this vulnerability. ### Workarounds Call `Plug.Conn.configure_session(conn, renew: true)` periodically and after privilege change. A custom authorization plug can be written where the `create/3` method should return the `conn` only after `Plug.Conn.configure_session/2` have been called on it. ### References https://github.com/danschultzer/pow/commit/578ffd3d8bb8e8a26077b644222186b108da474f https://www.owasp.org/index.php/Session_fixation