On macOS, when running a MySQL query, we see the following error:
```
java.lang.ClassCastException: class io.netty.channel.kqueue.KQueueEventLoopGroup cannot be cast to class io.netty.channel.EventLoopGroup
```
This is because of a `LinkageError`, caused because these classes exist both in the parent `server` module classpath, as well as in this plugin's classpath separately. To fix this, we removed this dependency from the server module.
But then, this caused a problem with how the `DNSResolver` class was being, well, resolved by the application class loader, vs the plugin class loader. This is a macOS specific problem, and doesn't affect other operating systems.
For this, we add just this package as a dependency to the MySQL plugin.
06c8210a3a