Add note describing behavior after eviction is cancelled

Longhorn 2238

Signed-off-by: Eric Weber <eric.weber@suse.com>

enhancements/20230905-automatically-evict-replicas-while-draining.md

@@ -142,6 +142,8 @@ The existing eviction logic is well-tested, so there is no reason to refactor it
   `replica.status.evictionRequested = false` on that replica.
 - The volume controller uses `replica.status.evictionRequested == false` to influence replica scheduling/deletion
   behavior (e.g. don't start a rebuild for a previously evicting replica if one hasn't been started already).
+- NOTE: If a new replica already started rebuilding as part of an eviction, it continues to rebuild and remains in the
+  cluster even after eviction is canceled. It can be cleaned up manually if desired.
 
 Make slight changes so that:
 
@@ -158,6 +160,8 @@ Make slight changes so that:
   `status.autoEvicting = false` on the appropriate `node.longhorn.io` object.
 - In addition to its pre-existing checks, if the replica controller sees `status.autoEvicting == false` on the node
   hosting a replica, it may set `status.evictionRequested = false` on that replica.
+- NOTE: If a new replica already started rebuilding as part of an automatic eviction, it continues to rebuild and
+  remains in the cluster even after eviction is canceled. It can be cleaned up manually if desired.
 
 ### Test plan