removed windows 2019 and ubuntu 20.04 files and reference

images/windows/scripts/build/Install-Mingw64.ps1

@@ -3,39 +3,9 @@
 ##  Desc:  Install GNU tools for Windows
 ################################################################################
 
-if (Test-IsWin19) {
-    # If Windows 2019, install version 8.1.0 form sourceforge
-    $baseUrl = "https://download.qt.io/development_releases/prebuilt"
-
-    $("mingw32", "mingw64") | ForEach-Object {
-        if ($_ -eq "mingw32") {
-            $url = "$baseUrl/mingw_32/i686-8.1.0-release-posix-dwarf-rt_v6-rev0.7z"
-            $sha256sum = 'adb84b70094c0225dd30187ff995e311d19424b1eb8f60934c60e4903297f946'
-        } elseif ($_ -eq "mingw64") {
-            $url = "$baseUrl/mingw_64/x86_64-8.1.0-release-posix-seh-rt_v6-rev0.7z"
-            $sha256sum = '853970527b5de4a55ec8ca4d3fd732c00ae1c69974cc930c82604396d43e79f8'
-        } else {
-            throw "Unknown architecture $_"
-        }
-
-        $packagePath = Invoke-DownloadWithRetry $url
-        Test-FileChecksum -Path $packagePath -ExpectedSHA256Sum $sha256sum
-        Expand-7ZipArchive -Path $packagePath -DestinationPath "C:\"
-
-        # Make a copy of mingw-make.exe to make.exe, which is a more discoverable name
-        # and so the same command line can be used on Windows as on macOS and Linux
-        $path = "C:\$_\bin\mingw32-make.exe" | Get-Item
-        Copy-Item -Path $path -Destination (Join-Path $path.Directory 'make.exe')
-    }
-
-    Add-MachinePathItem "C:\mingw64\bin"
-
-}
-
-if (-not (Test-IsWin19)) {
-    # If Windows 2022 0r 2025 install version specified in the toolset
-    $version = (Get-ToolsetContent).mingw.version
-    $runtime = (Get-ToolsetContent).mingw.runtime
+# Install version specified in the toolset
+$version = (Get-ToolsetContent).mingw.version
+$runtime = (Get-ToolsetContent).mingw.runtime
 
     $("mingw32", "mingw64") | ForEach-Object {
         if ($_ -eq "mingw32") {