Allow configuration of ThreadPool warning times (#81487)

We added some warn logging in #72465 but did not register the settings that
control the thresholds. This commit addresses that oversight.

server/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java

@@ -457,6 +457,8 @@ public void apply(Settings value, Settings current, Settings previous) {
         SearchModule.INDICES_MAX_CLAUSE_COUNT_SETTING,
         SearchModule.INDICES_MAX_NESTED_DEPTH_SETTING,
         ThreadPool.ESTIMATED_TIME_INTERVAL_SETTING,
+        ThreadPool.LATE_TIME_INTERVAL_WARN_THRESHOLD_SETTING,
+        ThreadPool.SLOW_SCHEDULER_TASK_WARN_THRESHOLD_SETTING,
         FastVectorHighlighter.SETTING_TV_HIGHLIGHT_MULTI_VALUE,
         Node.BREAKER_TYPE_KEY,
         OperationRouting.USE_ADAPTIVE_REPLICA_SELECTION_SETTING,