Use newest Npgsql when targeting net8.0 and above

Author: roji

dotnet/Directory.Packages.props

@@ -89,7 +89,8 @@
     <PackageVersion Include="ModelContextProtocol" Version="0.4.0-preview.3" />
     <PackageVersion Include="MSTest.TestFramework" Version="3.8.0" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
-    <PackageVersion Include="Npgsql" Version="8.0.7" />
+    <PackageVersion Include="Npgsql" Version="10.0.2" Condition="$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net8.0'))" />
+    <PackageVersion Include="Npgsql" Version="8.0.7" Condition="!$([MSBuild]::IsTargetFrameworkCompatible('$(TargetFramework)', 'net8.0'))" />
     <PackageVersion Include="OData2Linq" Version="2.2.0" />
     <PackageVersion Include="OllamaSharp" Version="5.4.12" />
     <PackageVersion Include="OpenAI" Version="2.9.1" />