Remove outdated Tiered Storage notice (#1089)

Author: kbatuigas

modules/manage/partials/tiered-storage.adoc

@@ -16,11 +16,6 @@ The following image illustrates the Tiered Storage architecture: remote write up
 
 image::shared:tiered_storage1.png[Tiered Storage architecture]
 
-[IMPORTANT]
-====
-When upgrading Redpanda, uploads to object storage are paused until all brokers in the cluster are upgraded. If the cluster gets stuck while upgrading, roll it back to the original version. In a mixed-version state, the cluster could run out of disk space. If you need to force a mixed-version cluster to upload, move partition leadership to brokers running the original version.
-====
-
 == Prerequisites
 
 include::shared:partial$enterprise-license.adoc[]