fix: mark BaseResource as abstract in resource manager initialization (#3893)

This change moves the abstract resource flag to the ResourceManager's initialize method, ensuring that the BaseResource is treated as abstract without requiring developers to modify the BaseResource class directly.

Author: Paul-Bob

app/avo/base_resource.rb

@@ -1,7 +1,5 @@
 module Avo
   class BaseResource < Avo::Resources::Base
-    abstract_resource!
-
     # Users can override this class to add custom methods for all resources.
   end
 end

lib/avo/resources/resource_manager.rb

@@ -41,7 +41,6 @@ def fetch_resources
           end
 
           # All descendants from Avo::Resources::Base except the internal abstract ones
-
           Base.descendants.reject { _1.is_abstract? }
         end
 
@@ -59,6 +58,11 @@ def load_configured_resources
       end
 
       def initialize
+        # Mark the BaseResource as abstract so it doesn't get loaded by the resource manager
+        # This is made here instead of in the BaseResource class because this class can be overridden
+        # And we don't want to force the developer that overrides this class to add the abstract resource flag to the overridden class.
+        Avo::BaseResource.abstract_resource!
+
         @resources = self.class.fetch_resources
       end