Bump MessagePack in /violet-message-search-core/hdownloader

Bumps [MessagePack](https://github.com/MessagePack-CSharp/MessagePack-CSharp) from 2.1.115 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@v2.1.115...v2.5.187)

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

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

violet-message-search-core/hdownloader/hdownloader.csproj

@@ -10,7 +10,7 @@
   <ItemGroup>
     <PackageReference Include="Extreme.Numerics" Version="7.0.12" />
     <PackageReference Include="HtmlAgilityPack" Version="1.11.24" />
-    <PackageReference Include="MessagePack" Version="2.1.115" />
+    <PackageReference Include="MessagePack" Version="2.5.187" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="SevenZipExtractor" Version="1.0.15" />
     <PackageReference Include="sqlite-net-pcl" Version="1.7.335" />