[Repo Assist] Remove FSI testing setup files (SetupTesting.fsx, Test.fsx) (#1666)

* Remove FSI testing setup files (SetupTesting.fsx, Test.fsx)

The library is no longer actively developed using FSI for testing/development.
Removes src/SetupTesting.fsx, src/Test.fsx, and updates the fsproj and
CONTRIBUTING.md accordingly.

Closes #1321

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* ci: trigger CI checks

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

CONTRIBUTING.md

@@ -87,10 +87,9 @@ between _runtime_ and _design-time_ components, so you'll find at least two file
 
 ### Debugging
 
-To debug the type generation, the best way is to change `FSharp.Data.DesignTime` project to a Console application,
-rename `Test.fsx` to `Test.fs` and hit the Run command in the IDE, setting the breakpoints where you need them.  
-This will invoke all the type providers manually without locking the files in Visual Studio / Xamarin Studio.  
-You'll also see in the console output the complete dump of the generated types and expressions.  
+To debug the type generation, the best way is to change `FSharp.Data.DesignTime` project to a Console application and hit the Run command in the IDE, setting the breakpoints where you need them.
+This will invoke all the type providers manually without locking the files in Visual Studio / Xamarin Studio.
+You'll also see in the console output the complete dump of the generated types and expressions.
 This is also the process used for the signature tests.
 
 ## Documentation

src/FSharp.Data.DesignTime/FSharp.Data.DesignTime.fsproj

@@ -33,7 +33,6 @@
     <Compile Include="Html/HtmlGenerator.fs" />
     <Compile Include="Html/HtmlProvider.fs" />
     <Compile Include="../AssemblyInfo.DesignTime.fs" />
-    <None Include="../Test.fsx" />
     <None Include="paket.references" />
   </ItemGroup>
   <ItemGroup>