chore(deps): bump MessagePack from 2.5.140 to 2.5.187 in /Shoko.Server

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] <[email protected]>

Shoko.Server/Shoko.Server.csproj

@@ -60,7 +60,7 @@
     <PackageReference Include="JetBrains.Annotations" Version="2023.3.0" />
     <PackageReference Include="Libuv" Version="1.10.0" />
     <PackageReference Include="Magick.NET-Q8-AnyCPU" Version="13.6.0" />
-    <PackageReference Include="MessagePack" Version="2.5.140" />
+    <PackageReference Include="MessagePack" Version="2.5.187" />
     <PackageReference Include="MessagePackAnalyzer" Version="2.5.140">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>