upgrade TargetFramework to net6.0

Author: Ahoo-Wang

sample/SmartSql.Sample.AspNetCore/SmartSql.Sample.AspNetCore.csproj

@@ -1,14 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
-    <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
+    <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
-
+  
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.App" />
-    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
-    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.2.4" />
     <PackageReference Include="SkyAPM.Agent.AspNetCore" Version="0.9.0" />
     <PackageReference Include="SkyAPM.Diagnostics.SmartSql" Version="0.9.0" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="4.0.1" />

src/SmartSql.DataConnector/SmartSql.DataConnector.csproj

@@ -1,8 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>netcoreapp2.2</TargetFramework>
+        <TargetFramework>net6.0</TargetFramework>
         <PackAsTool>true</PackAsTool>
         <ToolCommandName>SmartSql.DataConnector</ToolCommandName>
         <PackageOutputPath>./nupkg</PackageOutputPath>

src/SmartSql.Test.Performance/SmartSql.Test.Performance.csproj

@@ -1,8 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>