Get-DscResource returns classes without [DscResource()] attribute

Prerequisites

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[X] Make sure you are able to repro it on the latest released version
[X] Search the existing issues.

Steps to reproduce

If you have a module containing classes that do not have [DscResource()] attribute Get-DscResource will return those classes as if they were a resource.

PSDsc should check classes to see if they have that attribute and not return them.

Expected behavior

# classes without `[DscResource()]` are not returned as resources

Actual behavior

ImplementationDetail :
ResourceType         : Reason
Name                 : Reason
FriendlyName         :
Module               :
ModuleName           :
Version              :
Path                 :
ParentPath           :
ImplementedAs        : Binary
CompanyName          :
Properties           :

Error details

No response

Environment data

7.4-preview2

Version

2.0.6

Visuals