roachtest: deflake tpcc/multiregion

The test requires the schema to be unlocked to make a locality change.

Release note: None

Author: rafiss

pkg/workload/tpcc/tpcc.go

@@ -621,9 +621,16 @@ func (w *tpcc) Hooks() workload.Hooks {
 				// extraordinarily longer. If data is imported with IMPORT, this
 				// statement is idempotent.
 				if len(w.multiRegionCfg.regions) > 0 {
+					// Locality changes can only be made if schema_locked is toggled.
+					if _, err := db.Exec(`ALTER TABLE item SET (schema_locked=false)`); err != nil {
+						return err
+					}
 					if _, err := db.Exec(fmt.Sprintf(`ALTER TABLE item SET %s`, localityGlobalSuffix)); err != nil {
 						return err
 					}
+					if _, err := db.Exec(`ALTER TABLE item SET (schema_locked=true)`); err != nil {
+						return err
+					}
 				}
 			}