Add/redis tag cleanup info

[Isengo1989]

Add Redis Cache Tag Cleanup Documentation

What

Adds comprehensive documentation about Redis cache tag cleanup issues and solutions to the performance guides.

Why

Cache tags accumulate over time without proper cleanup, causing memory bloat in Redis. This addresses a common production issue with practical solutions.

Changes

• New "Redis Cache Tag Cleanup" section in guides/hosting/performance/caches.md
• Documents the problem, root causes, and solutions using FroshTools
• Includes automation examples and best practices for production environments

Key additions

• Problem explanation with Redis CLI verification examples
• FroshTools cleanup commands (frosh:redis-namespace:cleanup, frosh:redis-tag:cleanup)
• Deployment integration and cron job examples
• Best practices for Redis cache management

Fixes documentation gap for teams using Redis as cache backend with cache.adapter.redis_tag_aware.

[Isengo1989]

@shyim, not sure if this is not better suited in the core 🤔 ? I am not aware of how often this happens in production environments, and therefore, it should be addressed in-house.

[shyim]

Can we have here an experimental banner?

[Isengo1989]

4522d97

[Isengo1989]

Maybe we can move this to draft until the feature is out of the experimental phase. Also saw there is an open PR on this topic for some time

FriendsOfShopware/FroshTools#367