Bump Confluent.Kafka from 1.9.3 to 2.8.0

Bumps [Confluent.Kafka](https://github.com/confluentinc/confluent-kafka-dotnet) from 1.9.3 to 2.8.0.
- [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@v1.9.3...v2.8.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

src/Motor.Extensions.Hosting.Kafka/Motor.Extensions.Hosting.Kafka.csproj

@@ -5,7 +5,7 @@
 	</PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Confluent.Kafka" Version="1.9.3" />
+        <PackageReference Include="Confluent.Kafka" Version="2.8.0" />
         <PackageReference Include="CloudNative.CloudEvents.Kafka" Version="2.8.0" />
         <PackageReference Include="CloudNative.CloudEvents.SystemTextJson" Version="2.8.0" />
         <PackageReference Include="Microsoft.Extensions.Options" Version="9.0.1" />