fix(auth): sign out regardless of request success

[leoMehlig]

This lets the client reset the session, which is relevant if a logout fails (for example if the user is offline).

[grdsdev]

@leoMehlig if I understand this is used to fix an issue with the signOut not working when offline.

Looking at the flutter implementation again https://github.com/supabase/supabase-flutter/blob/main/packages/gotrue/lib/src/gotrue_client.dart#L844 it resets the session before making the request, so it will sign out regardless of the request succeeding or not. I think this is the way to go here.

Now that we have the currentSession without validating the session, it should be easy to implement the same behavior as the Flutter lib.

Let me know if you want to do it in this PR, or I should PR this changes I mentioned.

[leoMehlig]

Good point @grdsdev! I've adjusted the PR to do this and removed the resetSession function.

I had to use the execute instead of the authorizedExecute function and manually add the auth header. I think this is fine, but we could also refactor the authorizedExecute to allow passing in an accessToken.