Bump net.logstash.logback:logstash-logback-encoder from 8.1 to 9.0

Bumps [net.logstash.logback:logstash-logback-encoder](https://github.com/logfellow/logstash-logback-encoder) from 8.1 to 9.0.
- [Release notes](https://github.com/logfellow/logstash-logback-encoder/releases)
- [Commits](logfellow/logstash-logback-encoder@logstash-logback-encoder-8.1...logstash-logback-encoder-9.0)

---
updated-dependencies:
- dependency-name: net.logstash.logback:logstash-logback-encoder
  dependency-version: '9.0'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

app/build.gradle.kts

@@ -52,7 +52,7 @@ dependencies {
     implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.20.0")
     implementation("com.nimbusds:nimbus-jose-jwt:10.5")
     implementation("io.micrometer:micrometer-registry-prometheus:1.15.5")
-    implementation("net.logstash.logback:logstash-logback-encoder:8.1")
+    implementation("net.logstash.logback:logstash-logback-encoder:9.0")
     implementation("org.apache.kafka:kafka-streams:4.1.0")
     implementation("io.prometheus:prometheus-metrics-tracer-initializer:1.4.1")