C#: Remove ProjectTypeGuids from Godot.NET.Sdk

The property has no effect as the older VS project system doesn't
work with Sdk style projects.

The presence of the property was preventing Visual Studio for Mac
from opening the project if the Godot extension is not installed.

modules/mono/editor/Godot.NET.Sdk/Godot.NET.Sdk/Sdk/Sdk.props

@@ -2,8 +2,6 @@
   <PropertyGroup>
     <!-- Determines if we should import Microsoft.NET.Sdk, if it wasn't already imported. -->
     <GodotSdkImportsMicrosoftNetSdk Condition=" '$(UsingMicrosoftNETSdk)' != 'true' ">true</GodotSdkImportsMicrosoftNetSdk>
-
-    <GodotProjectTypeGuid>{8F3E2DF0-C35C-4265-82FC-BEA011F4A7ED}</GodotProjectTypeGuid>
   </PropertyGroup>
 
   <PropertyGroup>

modules/mono/editor/Godot.NET.Sdk/Godot.NET.Sdk/Sdk/Sdk.targets

@@ -1,11 +1,6 @@
 <Project>
   <Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" Condition=" '$(GodotSdkImportsMicrosoftNetSdk)' == 'true' " />
 
-  <PropertyGroup>
-    <EnableGodotProjectTypeGuid Condition=" '$(EnableGodotProjectTypeGuid)' == '' ">true</EnableGodotProjectTypeGuid>
-    <ProjectTypeGuids Condition=" '$(EnableGodotProjectTypeGuid)' == 'true' ">$(GodotProjectTypeGuid);$(DefaultProjectTypeGuid)</ProjectTypeGuids>
-  </PropertyGroup>
-
   <PropertyGroup>
     <!--
     Define constant to determine whether the real_t type in Godot is double precision or not.