docs(consensus): Update 09_decentralization.md (#2473)

docs/guides/external-node/09_decentralization.md

@@ -17,6 +17,12 @@ On the gossipnet, the data integrity will be protected by the BFT (byzantine fau
 > current implementation it may take a couple of hours and gets faster the more nodes you add to the
 > `gossip_static_outbound` list (see below). We are working to remove this inconvenience.
 
+
+> [!NOTE]
+>
+> The minimal supported server version for this is [24.11.0](https://github.com/matter-labs/zksync-era/releases/tag/core-v24.11.0)
+
+
 ### Generating secrets
 
 Each participant node of the gossipnet has to have an identity (a public/secret key pair). When running your node for