Bump Akka.Streams.Amqp.RabbitMq

Bumps [Akka.Streams.Amqp.RabbitMq](https://github.com/akkadotnet/Alpakka) from 1.5.8 to 1.5.15.
- [Release notes](https://github.com/akkadotnet/Alpakka/releases)
- [Changelog](https://github.com/akkadotnet/Alpakka/blob/dev/RELEASE_NOTES.md)
- [Commits](akkadotnet/Alpakka@1.5.8...1.5.15)

---
updated-dependencies:
- dependency-name: Akka.Streams.Amqp.RabbitMq
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

src/reliability/rabbitmq-backpressure/ReliableRabbitMQ.Shared/ReliableRabbitMQ.Shared.csproj

@@ -7,7 +7,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="Akka.Streams.Amqp.RabbitMq" Version="1.5.8" />
+        <PackageReference Include="Akka.Streams.Amqp.RabbitMq" Version="1.5.15" />
         <PackageReference Include="Akka.Cluster.Hosting" Version="$(AkkaHostingVersion)" />
     </ItemGroup>