Spring session PRINCIPAL_NAME_INDEX_NAME is not getting cleaned up after session is expired

[chittim412]

Describe the bug
"mysession:index:org.springframework.session.FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME:user" not cleaned up in redis when the session is expired

recently we were facing similar issue in the production, the uncleaned entries were huge and seeing some performance issue
could you please help to resolve this

To Reproduce
https://github.com/chittim412/demo.git --> checkout master
read readme file

libraries
spring boot 2.7.18
spring-session-data-redis:2.7.4
lettuce-core:6.1.10.RELEASE
redis running on docker
java 11

due to some internal issue we dont want to upgrade the system to spring boot 3 and java17

Expected behavior
"mysession:index:org.springframework.session.FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME:user" key should cleaned up in redis when the session is expired