Add Java formatting and lint checks

[Maayanshani25]

Integrate a Java formatter/linter and include lint checks as part of the test/build process to enforce consistent code style and automatically fail on violations.

[jeremyprime]

Deferring this for now. Any linting we apply should be minimal and align with spring-data-redis to make changes from upstream easier. Will revisit after the Spring Boot 4 migration.