Bump .NET SDK from 3.1.419 to 3.1.424 (PowerShell#1852)

* Bump .NET SDK from 3.1.102 to 3.1.424

* cleanup diff

Author: bergmeister

README.md

@@ -72,7 +72,7 @@ To install **PSScriptAnalyzer** from source code:
 
 ### Requirements
 
-- [.NET Core 3.1.102 SDK](https://www.microsoft.com/net/download/dotnet-core/3.1#sdk-3.1.102) or
+- [.NET Core 3.1.424 SDK](https://www.microsoft.com/net/download/dotnet-core/3.1#sdk-3.1.424) or
   newer patch release
 * If building for Windows PowerShell versions, then the .NET Framework 4.6.2 [targeting pack](https://dotnet.microsoft.com/en-us/download/dotnet-framework/net462) (also referred to as developer/targeting pack) need to be installed. This is only possible on Windows.
 * Optionally but recommended for development: [Visual Studio 2017/2019](https://www.visualstudio.com/downloads)

global.json

@@ -1,5 +1,5 @@
 {
     "sdk": {
-        "version": "3.1.419"
+        "version": "3.1.424"
     }
 }