Bump Confluent.Kafka from 2.5.3 to 2.6.0 (#692)

Bumps [Confluent.Kafka](https://github.com/confluentinc/confluent-kafka-dotnet) from 2.5.3 to 2.6.0.
- [Release notes](https://github.com/confluentinc/confluent-kafka-dotnet/releases)
- [Changelog](https://github.com/confluentinc/confluent-kafka-dotnet/blob/master/CHANGELOG.md)
- [Commits](confluentinc/confluent-kafka-dotnet@v2.5.3...v2.6.0)

---
updated-dependencies:
- dependency-name: Confluent.Kafka
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

src/Tingle.EventBus.Transports.Kafka/Tingle.EventBus.Transports.Kafka.csproj

@@ -10,7 +10,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Confluent.Kafka" Version="2.5.3" />
+    <PackageReference Include="Confluent.Kafka" Version="2.6.0" />
   </ItemGroup>
 
   <ItemGroup>