build(deps): bump confluent-kafka from 2.6.1 to 2.8.0 in /ci/builder

Bumps [confluent-kafka](https://github.com/confluentinc/confluent-kafka-python) from 2.6.1 to 2.8.0.
- [Release notes](https://github.com/confluentinc/confluent-kafka-python/releases)
- [Changelog](https://github.com/confluentinc/confluent-kafka-python/blob/master/CHANGELOG.md)
- [Commits](confluentinc/confluent-kafka-python@v2.6.1...v2.8.0)

---
updated-dependencies:
- dependency-name: confluent-kafka
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

ci/builder/requirements.txt

@@ -68,7 +68,7 @@ types-toml==0.10.8.20240310
 typing-extensions==4.12.2
 xxhash==3.5.0
 yamllint==1.35.1
-confluent-kafka==2.6.1
+confluent-kafka==2.8.0
 fastavro==1.10.0
 websocket-client==1.8.0
 pyarrow-stubs==17.16