Update CyberPrism.Core.csproj

<TargetFrameworks>net8.0;net8.0-windows7.0</TargetFrameworks>

Author: Forrest-tech

CyberPrism.Core/CyberPrism.Core.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0;net8.0-windows7.0</TargetFramework>
+    <TargetFrameworks>net8.0;net8.0-windows7.0</TargetFrameworks>
     <UseWPF>true</UseWPF>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>