[data-plane]: Bump cloudevents.sdk.version in /data-plane (#479)
[data-plane]: Bump cloudevents.sdk.version in /data-plane (#479)

Bumps `cloudevents.sdk.version` from 2.0.0.RC1 to 2.0.0.RC2.

Updates `cloudevents-http-vertx` from 2.0.0.RC1 to 2.0.0.RC2

Updates `cloudevents-kafka` from 2.0.0.RC1 to 2.0.0.RC2
- [Release notes](https://github.com/cloudevents/sdk-java/releases)
- [Commits](https://github.com/cloudevents/sdk-java/compare/2.0.0.RC1...2.0.0.RC2)

Updates `cloudevents-json-jackson` from 2.0.0.RC1 to 2.0.0.RC2

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

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
knative-sandbox/eventing-kafka-broker,knative-sandbox/eventing-kafka-broker,knative-sandbox/eventing-kafka-broker