make Redis Sendable

[AntVil]

These changes are now available in 4.11.1

• counter warning from Application.Redis: Stored property 'redisInstances' of 'Sendable'-conforming class 'MyRedis' has non-sendable type '[Application.Redis]'; this is an error in the Swift 6 language mode

example for more context:

extension Application {
    public final class MyRedis {
        struct MyRedisKey: StorageKey {
            typealias Value = Application.MyRedis
        }

        private let redisInstances: [Application.Redis]
    }
}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 53.33%. Comparing base (383ed57) to head (eb23c9e).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #217      +/-   ##
==========================================
+ Coverage   52.88%   53.33%   +0.45%     
==========================================
  Files          11       11              
  Lines         399      420      +21     
==========================================
+ Hits          211      224      +13     
- Misses        188      196       +8     

Files with missing lines	Coverage Δ
Sources/Redis/Application+Redis.swift	41.46% <ø> (ø)

... and 6 files with indirect coverage changes