Drop ZIP-archive support (#4485)

* Removed v19 related code from release workflow

* Chore: no more zip-archive

* Updated docs

---------

Co-authored-by: Ng Kiat Siong <[email protected]>

Author: Sven Reichel

.github/workflows/release.yml

@@ -3,4 +3,5 @@
 OpenMage provives differnt ways to install. We recommend to use [Composer](use-composer.md).
 If you want to contribute ot project, use [Git](use-git.md).
 
-You can also download latest [Release](use-tarball.md).
+!!! info
+    Since v20.11.0 installation from ZIP-archive is not supported anymore.

docs/content/users/install/index.md

@@ -161,7 +161,6 @@ nav:
           - users/install/index.md
           - users/install/use-composer.md
           - users/install/use-git.md
-          - users/install/use-tarball.md
           - users/install/secure-install.md
       - 'Changelog':
           - developers/changelog/index.md