Bump org.testcontainers:kafka from 1.21.3 to 1.21.4 in /start#396

dependabot[bot] wants to merge 1 commit intoprodOpenLiberty/guide-reactive-service-testing:prodfrom

dependabot/maven/start/org.testcontainers-kafka-1.21.4OpenLiberty/guide-reactive-service-testing:dependabot/maven/start/org.testcontainers-kafka-1.21.4Copy head branch name to clipboard