Data/MySQL compatibility with MySQL 9

[obiltschnig]

MySQL 9.0 has removed the mysql_native_password authentication plugin, which is apparently required by Data/MySQL.

https://blogs.oracle.com/mysql/post/mysql-90-its-time-to-abandon-the-weak-authentication-method

When attempting to connect, an error message regarding the removed plugin is printed to standard output.

Need to investigate what to do about it.