Upgrade go-redis from v8 to v9

[kumaramit01]

💸 TL;DR

This PR updates the go-redis library to v9. The v9 go-redis library is backward compatible with Redis 6 and supports Redis 7+. The existing v8 library doesn't support Redis 7. The v8 library fails for cluster slots, ping and error messages.

The managed client implementation has a dependency on v8 go-redis, that required some minor changes. The config options have changed in v9 specifically a new config ConnMaxLifetime that replaces MaxConnAge.

🧪 Testing Steps / Validation

We have tested go-redis with following redis version

Redis Version	go-redis version	Supported
6.2.13	8.x	Yes.
7.0.7	8.x	No.
7.2.3	8.x	No.
6.2.13	9.x	Yes.
7.0.7	9.x	Yes.
7.2.3	9.x	Yes.

✅ Checks

• CI tests (if present) are passing
• Adheres to code style for repo
• Contributor License Agreement (CLA) completed if not a Reddit employee

[fishy]

this is actually a breaking change, as code using it will need to change their usage of github.com/go-redis/redis/v8 into github.com/redis/go-redis/v9.

in general we just consider all the packages under github.com/reddit/baseplate.go/redis/ as deprecated and tell people to use the new internal redisbp instead. we just didn't mark them as deprecated as that will also break the existing code.

[kumaramit01]

Discussed offline -the support for v9 is via internal baseplate that has breaking changes.