auth: CachedTokenProviderOptions.DisableAutoRefresh returns nil token and nil err

[quartzmo]

The logic in cachedTokenProvider.Token does not check if the token is non-nil before returning it when cachedTokenProvider.autoRefresh is false.

Code

	tp := NewCachedTokenProvider(&countingTestProvider{count: 1}, &CachedTokenProviderOptions{
		DisableAutoRefresh: true,
	})
	freshToken, err := tp.Token(context.Background())
	if err != nil {
		fmt.Println(err)
	}
	if freshToken == nil {
		fmt.Println("freshToken is nil")
	}

Expected behavior

The CachedTokenProvider should fetch a new token the first time Token is called, even when DisableAutoRefresh is true.

Actual behavior

The CachedTokenProvider returns nil token and nil err the first time Token is called when DisableAutoRefresh is true.