Spring org.springframework.web.socket.server.standard.SpringConfiguratorTests has a configuration class that scans itself

In our efforts to get rid of bean overriding in the core framework, I've found a weird setup arrangement in SpringConfiguratorTests that as a @Configuration class that scans its own package. This has the outcome of registering the configuration class twice.

Given that the package has other tests, we should make this test setup more robust by not relying on classpath scanning.