Migrate Redis session repositories from DisposableBean to SmartLifecycle

[seung-hun-h]

This PR migrates RedisIndexedSessionRepository and ReactiveRedisIndexedSessionRepository from DisposableBean to SmartLifecycle to resolve compatibility issues with Spring Data Redis connection factories. The change ensures proper shutdown ordering and prevents Redis connection errors during application shutdown.

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Changes

• Replace DisposableBean with SmartLifecycle in Redis session repositories
• Add configurable lifecycle phase (default: Integer.MAX_VALUE / 2)
• Add unit tests for lifecycle behavior

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Related Issue

Fixes #3435