remove trailing comma

Author: bani

sql/mozfun/norm/result_type_to_product_name/udf.sql

@@ -94,7 +94,7 @@ RETURNS STRING AS (
         'restrict_keyword_tabs',
         'restrict_keyword_actions',
         'merino_market',
-        'important_dates',
+        'important_dates'
       )
       THEN res
     WHEN res LIKE('%opt_in')