Merge pull request #15198 from rook/mergify/bp/release-1.16/pr-15191

docs: Remove obsolete min csi version (backport #15191)

Documentation/Upgrade/rook-upgrade.md

@@ -202,9 +202,6 @@ kubectl -n $ROOK_OPERATOR_NAMESPACE set image deploy/rook-ceph-operator rook-cep
 !!! hint
     This is automatically updated if custom CSI image versions are not set.
 
-!!! important
-    The minimum supported version of Ceph-CSI is v3.8.0.
-
 Update to the latest Ceph-CSI drivers if custom CSI images are specified.
 See the [CSI Custom Images](../Storage-Configuration/Ceph-CSI/custom-images.md) documentation.