Remove outdated VS setup and 2019 support info

Removes VS 2019 from the list of supported IDEs. It doesn't support .NET SDK 6.0 and can't build Godot projects.

Removes mention of the VS extension. It only applies to 3.x projects and debugging is done with ordinary debugging tools after the move to .NET in 4.x.

tutorials/scripting/c_sharp/c_sharp_basics.rst

@@ -77,7 +77,6 @@ click on **Editor → Editor Settings** and scroll down to
 external editor of choice. Godot currently supports the following
 external editors:
 
-- Visual Studio 2019
 - Visual Studio 2022
 - Visual Studio Code
 - MonoDevelop
@@ -150,16 +149,6 @@ In Godot's **Editor → Editor Settings** menu:
 
 - Set **Dotnet** -> **Editor** -> **External Editor** to **Visual Studio**.
 
-Next, you can download the Godot Visual Studio extension from github
-`here <https://github.com/godotengine/godot-csharp-visualstudio/releases>`__.
-Double click on the downloaded file and follow the installation process.
-
-.. note:: The option to debug your game in Visual Studio may not appear after
-          installing the extension. To enable debugging, there is a
-          `workaround for Visual Studio 2019 <https://github.com/godotengine/godot-csharp-visualstudio/issues/10#issuecomment-720153256>`__.
-          There is
-          `a separate issue about this problem in Visual Studio 2022 <https://github.com/godotengine/godot-csharp-visualstudio/issues/28>`__.
-
 .. note:: If you see an error like "Unable to find package Godot.NET.Sdk",
           your NuGet configuration may be incorrect and need to be fixed.