Bump kafkaVersion from 3.7.0 to 7.8.0-ce

Bumps `kafkaVersion` from 3.7.0 to 7.8.0-ce.

Updates `org.apache.kafka:kafka-clients` from 3.7.0 to 7.8.0-ce

Updates `org.apache.kafka:kafka_2.13` from 3.7.0 to 7.8.0-ce

---
updated-dependencies:
- dependency-name: org.apache.kafka:kafka-clients
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: org.apache.kafka:kafka_2.13
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

build.gradle.kts

@@ -23,7 +23,7 @@ val postgresVersion = "42.7.4"
 val hikariVersion = "5.1.0"
 val flywayVersion = "10.21.0"
 val gsonVersion = "2.11.0"
-val kafkaVersion = "3.7.0"
+val kafkaVersion = "7.8.0-ce"
 val altinnKanalSchemasVersion = "2.0.0"
 val avroVersion = "1.12.0"
 val confluentVersion = "7.7.2"