fix plans

Author: max-hoffman

enginetest/plangen/testdata/spec.yaml

@@ -5,9 +5,8 @@ plans:
     path: enginetest/queries/index_query_plans.go
   - name: IntegrationPlanTests
     path: enginetest/queries/integration_plans.go
-# this suite is throwing a missing table error, despite the table being in the set up
-#  - name: TpchPlanTests
-#    path: enginetest/queries/tpch_plans.go
+  - name: TpchPlanTests
+    path: enginetest/queries/tpch_plans.go
   - name: TpccPlanTests
     path: enginetest/queries/tpcc_plans.go
 #  - name: TpcdsPlanTests