Bump MessagePack from 2.4.35 to 2.5.187 in /cs/playground/AsyncStress (…

…#927)

Bumps [MessagePack](https://github.com/MessagePack-CSharp/MessagePack-CSharp) from 2.4.35 to 2.5.187.
- [Release notes](https://github.com/MessagePack-CSharp/MessagePack-CSharp/releases)
- [Changelog](https://github.com/MessagePack-CSharp/MessagePack-CSharp/blob/master/prepare_release.ps1)
- [Commits](MessagePack-CSharp/MessagePack-CSharp@v2.4.35...v2.5.187)

---
updated-dependencies:
- dependency-name: MessagePack
  dependency-type: direct:production
...

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

cs/playground/AsyncStress/AsyncStress.csproj

@@ -9,7 +9,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="MessagePack" Version="2.4.35" />
+        <PackageReference Include="MessagePack" Version="2.5.187" />
         <PackageReference Include="xunit.assert" Version="2.4.2" />
     </ItemGroup>