Added Python 3.9.0 (#3970)

manifests/Python/Python/3.9.0.yaml

@@ -0,0 +1,21 @@
+  
+Id: Python.Python
+Version: 3.9.0
+Name: Python
+Publisher: Python
+License: PSF LICENSE AGREEMENT FOR PYTHON
+LicenseUrl: https://docs.python.org/3/license.html
+AppMoniker: python
+Tags: python, python3, programming language, script, glue language
+FileExtensions: py,pyw,pyc,pyo
+Description: Python is a programming language that lets you work more quickly and integrate your systems more effectively.
+Homepage: https://www.python.org
+Installers:
+  - Arch: x64
+    Url: https://www.python.org/ftp/python/3.9.0/python-3.9.0-amd64.exe
+    Sha256: FD2E2C6612D43BB6B213B72FC53F07D73D99059FA72C96E44BDE12E7815073AE
+    InstallerType: exe
+    Switches:
+      Silent: /Quiet
+      SilentWithProgress: /Passive
+      Custom: PrependPath=1