Remove the deprecated `:conditions` option in `INVALID_AUTOMATIC_INVERSE_OPTIONS`

This option was moved into active_record_deprecated_finders in ac4d101a.

activerecord/lib/active_record/reflection.rb

@@ -564,7 +564,7 @@ def polymorphic?
       end
 
       VALID_AUTOMATIC_INVERSE_MACROS = [:has_many, :has_one, :belongs_to]
-      INVALID_AUTOMATIC_INVERSE_OPTIONS = [:conditions, :through, :foreign_key]
+      INVALID_AUTOMATIC_INVERSE_OPTIONS = [:through, :foreign_key]
 
       def add_as_source(seed)
         seed