removed windows 2019 and ubuntu 20.04 files and reference

images/windows/scripts/build/Install-WDK.ps1

@@ -4,20 +4,11 @@
 ################################################################################
 
 # Requires Windows SDK with the same version number as the WDK
-if (Test-IsWin19) {
-    # Install all features without showing the GUI using winsdksetup.exe
-    Install-Binary -Type EXE `
-        -Url 'https://go.microsoft.com/fwlink/?linkid=2173743' `
-        -InstallArgs @("/features", "+", "/quiet") `
-        -ExpectedSubject $(Get-MicrosoftPublisher)
-
-    $wdkUrl = "https://go.microsoft.com/fwlink/?linkid=2166289"
-    $wdkExtensionPath = "C:\Program Files (x86)\Windows Kits\10\Vsix\VS2019\WDK.vsix"
-} elseif (Test-IsWin22) {
+if (Test-IsWin22) {
     # SDK is available through Visual Studio
     $wdkUrl = "https://go.microsoft.com/fwlink/?linkid=2324617"
 } else {
-    throw "Invalid version of Visual Studio is found. Either 2019 or 2022 are required"
+    throw "Invalid version of Visual Studio is found. Windows Server 2022 is required"
 }
 
 # Install all features without showing the GUI using wdksetup.exe
@@ -26,8 +17,4 @@ Install-Binary -Type EXE `
     -InstallArgs @("/features", "+", "/quiet") `
     -ExpectedSubject $(Get-MicrosoftPublisher)
 
-if (Test-IsWin19){
-    # Need to install the VSIX to get the build targets when running VSBuild
-    Install-VSIXFromFile (Resolve-Path -Path $wdkExtensionPath)
-}
 Invoke-PesterTests -TestFile "WDK"