test: fix redis not being used properly in imapClientFactoryTest #16629

Job	Run time
Nextcloud master php8.1 unit tests	1m 10s
Nextcloud master php8.1 unit tests	1m 10s
Nextcloud stable30 php8.1 unit tests	1m 10s
Nextcloud stable30 php8.1 unit tests	1m 10s
Nextcloud master php8.2 unit tests	3m 15s
Nextcloud master php8.2 unit tests	3m 15s
Front-end unit tests	1m 9s
Front-end unit tests	1m 9s
master w/ php8.3-sqlite-nocache integration tests	3m 17s
master w/ php8.3-sqlite-nocache integration tests	3m 17s
Nextcloud stable30 php8.2 unit tests	2m 55s
Nextcloud stable30 php8.2 unit tests	2m 55s
master w/ php8.3-mysql-nocache integration tests	3m 43s
master w/ php8.3-mysql-nocache integration tests	3m 43s
Nextcloud master php8.3 unit tests	2m 14s
Nextcloud master php8.3 unit tests	2m 14s
master w/ php8.3-pgsql-nocache integration tests	3m 16s
master w/ php8.3-pgsql-nocache integration tests	3m 16s
Nextcloud stable30 php8.3 unit tests	2m 15s
Nextcloud stable30 php8.3 unit tests	2m 15s
master w/ php8.1-sqlite-redis integration tests	10m 23s
master w/ php8.1-sqlite-redis integration tests	10m 23s
master w/ php8.2-mysql-redis integration tests	12m 9s
master w/ php8.2-mysql-redis integration tests	8m 40s
stable30 w/ php8.2-mysql-redis integration tests	11m 59s
stable30 w/ php8.2-mysql-redis integration tests	13m 1s
test-summary	4s
test-summary	1s
	1h 55m 28s

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