v9: cleanup Retry pipeline read commands

[vmihailenco]

See https://github.com/go-redis/redis/pull/1883

WARNING: DATA RACE
Read at 0x00c0005be268 by goroutine 162:
  github.com/go-redis/redis/v8.(*baseCmd).Err()
      /home/runner/work/redis/redis/command.go:171 +0x3e
  github.com/go-redis/redis/v8.(*StringCmd).Err()
      <autogenerated>:1 +0x44
  github.com/go-redis/redis/v8.setCmdsErr()
      /home/runner/work/redis/redis/command.go:34 +0x84
  github.com/go-redis/redis/v8.(*ClusterClient)._processTxPipeline.func1()
      /home/runner/work/redis/redis/cluster.go:1321 +0x2b5

Previous write at 0x00c0005be268 by goroutine 241:
  github.com/go-redis/redis/v8.(*baseCmd).SetErr()
      /home/runner/work/redis/redis/command.go:167 +0x3e
  github.com/go-redis/redis/v8.(*StringCmd).SetErr()
      <autogenerated>:1 +0x57
  github.com/go-redis/redis/v8.pipelineReadCmds()
      /home/runner/work/redis/redis/redis.go:467 +0xe3
  github.com/go-redis/redis/v8.(*ClusterClient)._processTxPipelineNode.func1.1.2()
      /home/runner/work/redis/redis/cluster.go:1372 +0x3e4
  github.com/go-redis/redis/v8/internal/pool.(*Conn).WithReader()
      /home/runner/work/redis/redis/internal/pool/conn.go:70 +0x13e
  github.com/go-redis/redis/v8.(*ClusterClient)._processTxPipelineNode.func1.1()
      /home/runner/work/redis/redis/cluster.go:1358 +0x24f
  github.com/go-redis/redis/v8.(*baseClient).withConn()
      /home/runner/work/redis/redis/redis.go:298 +0x3ec
  github.com/go-redis/redis/v8.(*ClusterClient)._processTxPipelineNode.func1()
      /home/runner/work/redis/redis/cluster.go:1350 +0x1e4
  github.com/go-redis/redis/v8.hooks.processPipeline.func1()
      /home/runner/work/redis/redis/redis.go:93 +0x3db
  github.com/go-redis/redis/v8.hooks.withContext()
      /home/runner/work/redis/redis/redis.go:132 +0x38f
  github.com/go-redis/redis/v8.hooks.processPipeline()
      /home/runner/work/redis/redis/redis.go:92 +0x38e
  github.com/go-redis/redis/v8.hooks.processTxPipeline()
      /home/runner/work/redis/redis/redis.go:128 +0x43c
  github.com/go-redis/redis/v8.(*ClusterClient)._processTxPipelineNode()
      /home/runner/work/redis/redis/cluster.go:1349 +0x126
  github.com/go-redis/redis/v8.(*ClusterClient)._processTxPipeline.func1()
      /home/runner/work/redis/redis/cluster.go:1311 +0xea