Bump confluentVersion from 7.8.0 to 7.9.0

Bumps `confluentVersion` from 7.8.0 to 7.9.0.

Updates `io.confluent:kafka-streams-json-schema-serde` from 7.8.0 to 7.9.0
- [Commits](confluentinc/schema-registry@v7.8.0...v7.9.0)

Updates `io.confluent:kafka-schema-registry-client` from 7.8.0 to 7.9.0
- [Commits](confluentinc/schema-registry@v7.8.0...v7.9.0)

---
updated-dependencies:
- dependency-name: io.confluent:kafka-streams-json-schema-serde
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.confluent:kafka-schema-registry-client
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

build.gradle.kts

@@ -36,7 +36,7 @@ val junitVersion = "5.12.0"
 val junitPioneerVersion = "2.3.0"
 val mockitoVersion = "5.15.2"
 val jmhVersion = "1.37"
-val confluentVersion = "7.8.0"
+val confluentVersion = "7.9.0"
 val vertxVersion = "4.5.13"
 
 dependencies {