Revert "FIX: Drop function first before removing trigger."

This reverts commit d229969afa.

lib/column_dropper.rb

@@ -31,8 +31,8 @@ class ColumnDropper
 
       columns.each do |column|
         ActiveRecord::Base.exec_sql <<~SQL
-        DROP FUNCTION IF EXISTS #{readonly_function_name(table, column)};
         DROP TRIGGER IF EXISTS #{readonly_trigger_name(table, column)} ON #{table};
+        DROP FUNCTION IF EXISTS #{readonly_function_name(table, column)};
         SQL
 
         # safe cause it is protected on method entry, can not be passed in params