Update target framework to net8.0 and add UseRidGraph property

Author: Yeming Liu

tools/Az.Tools.Predictor/Directory.Build.props

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <Version>1.1.3</Version>
@@ -13,6 +13,11 @@
     <LangVersion>Latest</LangVersion>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <!-- https://learn.microsoft.com/en-us/dotnet/core/tools/sdk-errors/netsdk1206 -->
+    <UseRidGraph>true</UseRidGraph>
+  </PropertyGroup>
+
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <DefineConstants>DEBUG;TRACE</DefineConstants>
   </PropertyGroup>