MDEV-23593 : galera_3nodes.GCF-376 MTR failed: Table 'test.t1' doesn't exist

Add wait_condition to make sure table is there.

mysql-test/suite/galera_3nodes/t/GCF-376.test

@@ -17,6 +17,9 @@
 CREATE TABLE test.t1 (f1 INTEGER PRIMARY KEY, f2 CHAR(1)) ENGINE=InnoDB;
 
 --connection node_2
+--let $wait_condition = SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 't1';
+--source include/wait_condition.inc
+
 SET GLOBAL wsrep_on=OFF;
 INSERT INTO t1 VALUES (1, 'a');
 SET GLOBAL wsrep_on=ON;