Simplify tpc-ds q34, q73 a bit to help an optimizer (#7969)

Author: zverevgeny

ydb/library/benchmarks/queries/tpcds/yql/q34.sql

@@ -22,10 +22,7 @@ select c_last_name
     and (household_demographics.hd_buy_potential = '>10000' or
          household_demographics.hd_buy_potential = 'Unknown')
     and household_demographics.hd_vehicle_count > 0
-    and (case when household_demographics.hd_vehicle_count > 0
-	then household_demographics.hd_dep_count/ household_demographics.hd_vehicle_count
-	else null
-	end)  > 1.2
+    and household_demographics.hd_dep_count / household_demographics.hd_vehicle_count > 1.2
     and date_dim.d_year in (2000,2000+1,2000+2)
     and store.s_county in ('Salem County','Terrell County','Arthur County','Oglethorpe County',
                            'Lunenburg County','Perry County','Halifax County','Sumner County')

ydb/library/benchmarks/queries/tpcds/yql/q73.sql

@@ -22,8 +22,7 @@ select c_last_name
     and (household_demographics.hd_buy_potential = '>10000' or
          household_demographics.hd_buy_potential = '5001-10000')
     and household_demographics.hd_vehicle_count > 0
-    and case when household_demographics.hd_vehicle_count > 0 then
-             household_demographics.hd_dep_count/ household_demographics.hd_vehicle_count else null end > 1
+    and household_demographics.hd_dep_count / household_demographics.hd_vehicle_count > 1
     and date_dim.d_year in (2000,2000+1,2000+2)
     and store.s_county in ('Lea County','Furnas County','Pennington County','Bronx County')
     group by store_sales.ss_ticket_number,store_sales.ss_customer_sk) dj cross join {{customer}} as customer