Bump ModelContextProtocol from 0.3.0-preview.2 to 0.3.0-preview.4

---
updated-dependencies:
- dependency-name: ModelContextProtocol
  dependency-version: 0.3.0-preview.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Directory.Packages.props

@@ -8,7 +8,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageVersion>
-    <PackageVersion Include="ModelContextProtocol" Version="0.3.0-preview.2" />
+    <PackageVersion Include="ModelContextProtocol" Version="0.3.0-preview.4" />
     <PackageVersion Include="Microsoft.Extensions.Hosting" Version="10.0.0-rc.2.25502.107" />
     <!-- Roslyn Scripting -->
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="4.14.0" />