Update ASP.NET Core version (#40)

Bump version 6 -> 8

Author: artem-kurchenko

ASP.NET Core/ASP.NET Core.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>
   <Target Name="DebugEnsureNodeEnv" BeforeTargets="BeforeBuild" Condition=" '$(Configuration)' == 'Debug' And !Exists('$(SpaRoot)node_modules') ">
     <!-- Ensure Node.js is installed -->