ci: add async-redis to iterations per second for a benchmark

[supercaracal]

https://github.com/socketry/async-redis

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# single
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ruby 3.3.4 (2024-07-09 revision be1089c8ec) [x86_64-linux]
Warming up --------------------------------------
         single: cli   118.000 i/100ms
       single: envoy    36.000 i/100ms
      single: cproxy    53.000 i/100ms
Calculating -------------------------------------
         single: cli      1.195k (± 5.7%) i/s -      6.018k in   5.053942s
       single: envoy    367.100 (± 3.8%) i/s -      1.872k in   5.107732s
      single: cproxy    531.992 (± 2.3%) i/s -      2.703k in   5.083637s

Comparison:
         single: cli:     1194.9 i/s
      single: cproxy:      532.0 i/s - 2.25x  slower
       single: envoy:      367.1 i/s - 3.26x  slower

ruby 3.3.4 (2024-07-09 revision be1089c8ec) [x86_64-linux]
Warming up --------------------------------------
       single: async    58.000 i/100ms
Calculating -------------------------------------
       single: async    577.182 (± 5.2%) i/s -      2.900k in   5.040221s