chore(deps): update kotlin to v1.9.21

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
org.jetbrains.kotlin.kapt	1.9.20 -> 1.9.21
org.jetbrains.kotlin.plugin.spring	1.9.20 -> 1.9.21
org.jetbrains.kotlin.jvm	1.9.20 -> 1.9.21

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (d198f48) 75.24% compared to head (44661c5) 75.24%.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #301   +/-   ##
=========================================
  Coverage     75.24%   75.24%           
  Complexity      306      306           
=========================================
  Files            69       69           
  Lines          1353     1353           
  Branches        154      154           
=========================================
  Hits           1018     1018           
  Misses          199      199           
  Partials        136      136           

Flag	Coverage Δ
unittests	75.24% <ø> (ø)

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