[Backport] [2.19] Bump netty from 4.1.118.Final to 4.1.121.Final (#18192)

[reta]

Backport of #18192 to 2.19

[github-actions]

✅ Gradle check result for e937d41: SUCCESS

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 72.04%. Comparing base (e53c0c8) to head (e937d41).
Report is 1 commits behind head on 2.19.

Additional details and impacted files

@@             Coverage Diff              @@
##               2.19   #18210      +/-   ##
============================================
- Coverage     72.07%   72.04%   -0.04%     
+ Complexity    66053    65976      -77     
============================================
  Files          5341     5341              
  Lines        307182   307182              
  Branches      44832    44832              
============================================
- Hits         221415   221306     -109     
- Misses        67319    67433     +114     
+ Partials      18448    18443       -5     

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