Use .NET 7 for Cake build

Author: bdukes

Build/Build.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net7.0</TargetFramework>
     <PackAsTool>true</PackAsTool>
     <!-- Make sure start same folder .NET Core CLI and Visual Studio -->
     <RunWorkingDirectory>$(MSBuildProjectDirectory)</RunWorkingDirectory>