Ignore generated methods for Memoized annotation for plugin validation

[wolfs]

Our current work validation (ValidatePlugins task) finds a problem with this method in the Gradle docker plugin:

    @Internal
    @Memoized
    DockerClient getDockerClient() {
        ...
    }

Namely, it reports non-property method 'memoizedMethodPriv\$getDockerClient()' should not be annotated with: @Internal.

We should ignore these methods generated by Groovy either altogether or the method generated by the @Memoized annotation in particular.

---

cc: @gradle/execution