galera.galera_gcache_recover_manytrx sporadic test failures

galera.galera_gcache_recover_manytrx test fails sporadically in 10.5 and later for a warning in error log:
[ERROR] Error in Log_event::read_log_event(): 'Event truncated', data_len: 1048618, event_type: 23
The test has warning suppression for this message, but it appears to be ineffective.
The suppression was modified in July 2023 as part of large merge from 10.4, and then entered in form:
call mtr.add_suppression("Error in Log_event::read_log_event():.*");

however, the quotations in error message string don't work as planned