Bump com.fasterxml.jackson.datatype:jackson-datatype-jdk8

Bumps com.fasterxml.jackson.datatype:jackson-datatype-jdk8 from 2.16.1 to 2.18.1.

---
updated-dependencies:
- dependency-name: com.fasterxml.jackson.datatype:jackson-datatype-jdk8
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

fluency-treasuredata/build.gradle.kts

@@ -4,6 +4,6 @@ dependencies {
   implementation("com.treasuredata.client:td-client:1.1.1")
   implementation("com.google.guava:guava:33.1.0-jre")
   testImplementation("com.fasterxml.jackson.datatype:jackson-datatype-json-org:2.16.1")
-  testImplementation("com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.16.1")
+  testImplementation("com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.18.1")
   implementation("com.squareup.okhttp3:okhttp:3.14.9")
 }