Update Kotlin core dependencies to v1.9.21-1.0.16

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
com.google.devtools.ksp (source)	1.9.21-1.0.15 -> 1.9.21-1.0.16
com.google.devtools.ksp:symbol-processing-api (source)	1.9.21-1.0.15 -> 1.9.21-1.0.16

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Release Notes

google/ksp (com.google.devtools.ksp)

### [`v1.9.21-1.0.16`](https://togithub.com/google/ksp/releases/tag/1.9.21-1.0.16) [Compare Source](https://togithub.com/google/ksp/compare/1.9.21-1.0.15...1.9.21-1.0.16) ##### Issue fixed [#​1653](https://togithub.com/google/ksp/issues/1653) KSP 1.9.21-1.0.15 leaking memory and causing OOMs

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Configuration

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (4455c83) 78.42% compared to head (66f49da) 78.42%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1870 +/- ## ========================================= Coverage 78.42% 78.42% Complexity 2465 2465 ========================================= Files 134 134 Lines 8695 8695 Branches 2199 2199 ========================================= Hits 6819 6819 Misses 897 897 Partials 979 979 ```

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[github-actions[bot]]

JUnit Tests (macOS, EnricoMi/publish-unit-test-result-action@v2)

   166 files  ±0     166 suites  ±0   5m 12s :stopwatch: +13s 1 426 tests ±0  1 388 :heavy_check_mark: ±0  38 :zzz: ±0  0 :x: ±0  2 805 runs  ±0  2 767 :heavy_check_mark: ±0  38 :zzz: ±0  0 :x: ±0 

Results for commit 16d66e1f. ± Comparison against base commit 8b44e13e.

[github-actions[bot]]

JUnit Tests (Windows, EnricoMi/publish-unit-test-result-action@v2)

   166 files  ±0     166 suites  ±0   7m 9s :stopwatch: -22s 1 426 tests ±0  1 409 :heavy_check_mark: ±0  17 :zzz: ±0  0 :x: ±0  2 805 runs  ±0  2 788 :heavy_check_mark: ±0  17 :zzz: ±0  0 :x: ±0 

Results for commit 16d66e1f. ± Comparison against base commit 8b44e13e.