Issue description

I'm connecting to MySQL using a password (token) generated through AWS IAM (https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/UsingWithRDS.IAMDBAuth.Connecting.Go.html#UsingWithRDS.IAMDBAuth.Connecting.GoV2).

So the user needs to be created with a specific authentication and not "just" password:
CREATE USER jane_doe IDENTIFIED WITH AWSAuthenticationPlugin AS 'RDS'; (but the token is still a password that expire after 15 minutes).

When I use that token or even a random input (invalid password, of course) with that user, I receive the message that i'm not using a password.
Error 1045 (28000): Access denied for user 'XXXX'@'YY.YY.YY.YY' (using password: NO)

The weird thing is the (using password: NO) is just with my code, but in terminal the behaviour is OK (even with an incorrect password - just to ensure). To test if the token generation is valid or not, I printed the token generated with my code and I used it in the terminal (mysql -h ... -u .... -p(token)) and it works fine.

My last test, just to ensure if users without IAM authentication have the same behaviour, I tried with another user (without IAM auth - traditional password access) with an invalid password, and I'm receiving the expected output: Error 1045 (28000): Access denied for user 'XXXX'@'YY.YY.YY.YY' (using password: YES)

I changed all the settings that I can, but is still not working. I don't know if is a problem from my side or it's a lib issue.

Example code

	username := m.Username
	password, err := auth.BuildAuthToken(
		m.ctx, endpoint, m.Region, m.Username, m.Creds,
	)
	if err != nil {
		return err
	}
	cfg := mysql.NewConfig()
	cfg.User = username
	cfg.Passwd = password
	cfg.Net = "tcp"
	cfg.Addr = endpoint
	cfg.DBName = "XXXXX"
	cfg.AllowCleartextPasswords = true
	cfg.ParseTime = true
	fmt.Printf("%+v\n", cfg)
	connector, err := mysql.NewConnector(cfg)
	if err != nil {
		return err
	}
	db := sql.OpenDB(connector)

Error log

2024年03月23日T15:43:59.536-0300 ERROR provisioner/router.go:91 error getting databases {"error": "Error 1045 (28000): Access denied for user 'XXX'@'YY.YY.YY.YY' (using password: NO)"}

Configuration

Driver version (or git SHA): v1.8.0

Go version: go1.21.5 linux/amd64

Server version: MySQL 8.0.28

Server OS: AWS RDS