metropolis: renamed DISOWNED to DECOMMISSIONED

This seems like a better name, and the old one was never actually used
anywhere.

Change-Id: I66b17a9145225828bb978c999bbecd5118188389
Reviewed-on: https://review.monogon.dev/c/monogon/+/2269
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/proto/common/common.proto b/metropolis/proto/common/common.proto
index 28becd3..d2b307e 100644
--- a/metropolis/proto/common/common.proto
+++ b/metropolis/proto/common/common.proto
@@ -85,9 +85,11 @@
     // The node is now ready to serve, and its certificate can be used to
     // authenticate its identity cryptographically.
     NODE_STATE_UP = 3;
-    // DISOWNED: the node has been rejected or decommissioned by the cluster.
-    // Any further contact from the node to the cluster will be rejected.
-    NODE_STATE_DISOWNED = 4;
+    // DECOMMISSIONED: The node has successfully been decommissioned and can be
+    // deleted.
+    //
+    // TODO(q3k): add missing -ING states.
+    NODE_STATE_DECOMMISSIONED = 4;
 };
 
 // ClusterState is the state of the cluster from the point of view of a node.