build(deps): bump com.google.crypto.tink:tink from 1.20.0 to 1.21.0 (#5683)

Bumps [com.google.crypto.tink:tink](https://github.com/tink-crypto/tink-java) from 1.20.0 to 1.21.0.
- [Release notes](https://github.com/tink-crypto/tink-java/releases)
- [Commits](tink-crypto/tink-java@v1.20.0...v1.21.0)

---
updated-dependencies:
- dependency-name: com.google.crypto.tink:tink
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -38,7 +38,7 @@ swagger = "2.2.42"
 titanium = "1.7.0"
 kafkaClients = "4.2.0"
 testcontainers = "2.0.4"
-tink = "1.20.0"
+tink = "1.21.0"
 dsp-tck = "1.0.0-RC6"
 dcp-tck = "1.0.0-RC6"
 junit = "6.0.3"