Remove 1 of 2 'alpha'-designated version of 7-Zip from non-alpha listing (#3762)

* Remove 'alpha'-designated versions from non-alpha listing

* delete only one alpha

* Revert "delete only one alpha"

This reverts commit 479beb65ec74fc6cc8755bd739da74261364efa9.

* Revert "Revert "delete only one alpha""

This reverts commit 47adb7d4f1d3fe83007cb58d6fe4884c05bf797c.

manifests/7Zip/7Zip/20.0.0-alpha.yaml

@@ -1,20 +0,0 @@
-Id: 7zip.7zip
-Name: 7Zip
-AppMoniker: 7zip
-Version: 20.0.0-alpha
-Publisher: 7zip
-Author: 7zip
-License: Copyright (C) 1999-2020 Igor Pavlov. - GNU LGPL
-LicenseUrl: https://7-zip.org/license.txt
-MinOSVersion: 10.0.0.0
-Homepage: https://www.7-zip.org/
-Description: Free and open source file archiver with a high compression ratio.
-Tags: "7zip,compression,file compression,utility,tool,zip"
-InstallerType: exe
-Installers: 
-  - Arch: x64 
-    Url: https://7-zip.org/a/7z2000-x64.exe
-    Sha256: 93b1739c237179186d4da1a6c0e821e208663915d3f1bbd7a4377d96aa6894a4
-    Switches:
-      Silent: /S
-      SilentWithProgress: /S