Fix Quarkus sample #373
Description
Quarkus sample broke with #337 due to a hanging attempt to get Spanner sessions in SessionClient.internalBatchCreateSessions().
It would be useful to test https://github.com/quarkiverse/quarkus-google-cloud-services/tree/main/spanner to understand whether the issue is reproducible with the client library, or if it's a combination of JDBC driver and Hibernate dialect.
Re-enable the integration test after fixing.