Bump com.fasterxml.jackson:jackson-bom from 2.20.1 to 2.21.0

Bumps [com.fasterxml.jackson:jackson-bom](https://github.com/FasterXML/jackson-bom) from 2.20.1 to 2.21.0.
- [Commits](FasterXML/jackson-bom@jackson-bom-2.20.1...jackson-bom-2.21.0)

---
updated-dependencies:
- dependency-name: com.fasterxml.jackson:jackson-bom
  dependency-version: 2.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -6,7 +6,7 @@ okio = "3.16.4"
 serialization = "1.9.0"
 benchmark = "0.4.15"
 openapi = "2026.1"
-jackson = "2.20.1"
+jackson = "2.21.0"
 
 [plugins]
 kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }