downgrade dependencies

Author: WeihanLi

projects/RabbitMQ.Client/RabbitMQ.Client.csproj

@@ -66,16 +66,16 @@
       Note: do NOT upgrade this dependency unless necessary
       See https://github.com/rabbitmq/rabbitmq-dotnet-client/pull/1481#pullrequestreview-1847905299
     -->
-    <PackageReference Include="System.IO.Pipelines" Version="7.0.0" />
+    <PackageReference Include="System.IO.Pipelines" Version="6.0.0" />
   </ItemGroup>
 
   <ItemGroup Condition="$(TargetFramework) == 'netstandard2.0'">
     <!--
       Note: do NOT upgrade these dependencies unless necessary
       See https://github.com/rabbitmq/rabbitmq-dotnet-client/pull/1481#pullrequestreview-1847905299
     -->
-    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="7.0.2" />
+    <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="6.0.0" />
     <PackageReference Include="System.Memory" Version="4.5.5" />
-    <PackageReference Include="System.Threading.Channels" Version="7.0.0" />
+    <PackageReference Include="System.Threading.Channels" Version="6.0.0" />
   </ItemGroup>
 </Project>