(cleanup) redis-namespace no longer works

[joshgoebel]

Via #719:

redis namespace is no longer needed thanks to #722.

---

And it no longer appears to work. The flipper-redis gem's use of with seems to bypass the namespacing provided by redis-namespace entirely:

irb(main):037> r
=> <Redis::Namespace v1.11.0 with client v4.8.1 for redis://redis:6379/0/cmm:namespace>
irb(main):038> c
=> #<Redis client v4.8.1 for redis://redis:6379/0>
irb(main):039> r.set("one", true)
=> "OK"
irb(main):041> r.with { |c| c.set("two","true") }
=> "OK"
irb(main):042> c.keys
=>
[
 "two",
 "cmm:namespace:one"
]

Am I missing something?