fix: Pin redis-py to 4.5.5 and enhance logging for Redis reconnection and failover

[achimnol]

refs #1443

This PR includes several critical fixes:

• Upgrade redis-py (4.6.0 → 5.0.1) to get the latest bug fixes related with garbage collection of socket connections and timeout detection on pipelined commands
  • redis-py 5.0.0 and 5.0.1 have numerous issues related with connection pool handling, especially with the async version of BlockingConnectionPool. We need to wait until redis-py stabilizes........
  • This PR pins the redis-py version 4.5.5 before it introduces the connection leak due to removal of Connection.__del__().
  • Explicitly pass auto_close_connection_pool=True (NOTE: Missing of this parameter is fixed in redis-py 5.0.0 and deprecated in 5.0.1, but the whole upstream package is broken now.)
  • Set max_connections to 16 per connection pool instead of the default 2**31.... (!!)
• Enhance logging for retries of Redis connection with explicit names for all connection pool instances
• Fix a bug in manager.registry.handle_kernel_log() to avoid creating a new Redis connection pool upon every container destruction request

Related upstream issues

• "No connection available" errors since 5.0.1 redis/redis-py#2995
• Instantiating BlockingConnectionPool.from_url with timeout in query args fails redis/redis-py#2983
• The connection is closed by Connection closed by server. redis/redis-py#2974
• Possible regression in 5.0.1: AttributeError: 'NoneType' object has no attribute 'feed' redis/redis-py#2967
• The close() method of socket should not be called in __del__ method. redis/redis-py#2891
• Max recursion depth RecursionError when max clients exceeded with Sentinel redis/redis-py#2866
• Is async version of redis-py coroutine safe? redis/redis-py#2835
• Blocking command timeout cannot exceed client's socket_timeout redis/redis-py#2807
• "Connection closed by server." redis/redis-py#2773
• Restarting Redis server causes "AttributeError: 'NoneType' object has no attribute 'decode'" redis/redis-py#2214
• Reduce default max_connections number redis/redis-py#2220
• Fix ConnectionPool deadlock triggered by gc redis/redis-py#3000

Checklist: (if applicable)

• Milestone metadata specifying the target backport version

[achimnol]

Made an upstream report: redis/redis-py#3008