[BugFix] allow partition ttl for statistics database (backport #54398) (

#54413)

Co-authored-by: Murphy <[email protected]>

fe/fe-core/src/main/java/com/starrocks/clone/DynamicPartitionScheduler.java

@@ -687,10 +687,7 @@ private void findSchedulableTables() {
         long start = System.currentTimeMillis();
         for (Long dbId : GlobalStateMgr.getCurrentState().getLocalMetastore().getDbIds()) {
             Database db = GlobalStateMgr.getCurrentState().getDb(dbId);
-            if (db == null) {
-                continue;
-            }
-            if (db.isSystemDatabase() || db.isStatisticsDatabase()) {
+            if (db == null || db.isSystemDatabase()) {
                 continue;
             }