Exclude ar_internal_metadata from DB cleaner

There's a bug in DatabaseCleaner where it deletes
ar_internal_metadata when cache_tables is false

spec/support/db_cleaner.rb

 # frozen_string_literal: true
 
 module DbCleaner
-  def delete_from_all_tables!(except: nil)
+  def delete_from_all_tables!(except: [])
+    except << 'ar_internal_metadata'
+
     DatabaseCleaner.clean_with(:deletion, cache_tables: false, except: except)
   end