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

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
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -8,7 +8,7 @@ foojay-resolver = "1.0.0"
 
 # Dependencies
 simplesocks = "1.0.1"
-tink = "1.20.0"
+tink = "1.21.0"
 jbcrypt = "1.0.2"
 kyber = "2.0.1"
 logback = "1.5.32"