[BUG][CLI] del-node fails to delete unreachable nodes #3208

Describe the bug

The valkey-cli --cluster del-node command reports a misleading [ERR] No such node ID when attempting to delete unreachable nodes, even though the node clearly exists in the cluster topology.

This is inconsistent with the instance-level CLUSTER FORGET command, which successfully removes unreachable nodes. The cluster-level wrapper should provide the same functionality.

To reproduce

1. Create a cluster with an unreachable node:

91b0f394a6052a8302415097dd9eed909adc0edb 127.0.0.1:7000@17000 myself,master - 0 0 1 connected 0-16383
df0ffd8d6071ed896f3c440925abb6f729de244d 127.0.0.1:7002@17002 slave,fail

2. Attempt to delete the failed node:

valkey-cli --cluster del-node 127.0.0.1:7000 df0ffd8d6071ed896f3c440925abb6f729de244d

3. Observe the error:

Could not connect to Valkey at 127.0.0.1:7002: Connection refused
>>> Removing node df0ffd8d6071ed896f3c440925abb6f729de244d from cluster 127.0.0.1:7000
[ERR] No such node ID df0ffd8d6071ed896f3c440925abb6f729de244d

Expected behavior

The del-node command should successfully remove unreachable nodes from the cluster, similar to how instance-level CLUSTER FORGET works.

Workaround

Manually execute CLUSTER FORGET <node-id> on all nodes within the cluster-blacklist-ttl period.