cluster: fix test, revert known_issue so it fails now

Author: alexfernandez

test/known_issues/test-cluster-import-scheduling-policy.mjs

@@ -1,6 +1,7 @@
 // Refs: https://github.com/nodejs/node/issues/49240
 // When importing cluster in ESM, cluster.schedulingPolicy cannot be set;
 // and the env variable doesn't work since imports are hoisted to the top.
+// Therefore the scheduling policy is still cluster.SCHED_RR.
 import '../common/index.mjs';
 import assert from 'node:assert';
 import * as cluster from 'cluster';
@@ -9,4 +10,4 @@ import * as cluster from 'cluster';
 assert.strictEqual(cluster.schedulingPolicy, cluster.SCHED_RR);
 cluster.setupPrimary({ schedulingPolicy: cluster.SCHED_NONE });
 const settings = cluster.getSettings();
-assert.strictEqual(settings.schedulingPolicy, cluster.SCHED_NONE);
+assert.strictEqual(settings.schedulingPolicy, cluster.SCHED_RR);