Bump MessagePack from 2.5.140 to 2.5.187 in /src/Foundatio.MessagePack

Bumps [MessagePack](https://github.com/MessagePack-CSharp/MessagePack-CSharp) from 2.5.140 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@v2.5.140...v2.5.187)

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

Signed-off-by: dependabot[bot] <support@github.com>

src/Foundatio.MessagePack/Foundatio.MessagePack.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <ItemGroup>
-    <PackageReference Include="MessagePack" Version="2.5.140" />
+    <PackageReference Include="MessagePack" Version="2.5.187" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Foundatio\Foundatio.csproj" />