core: task migration

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "3.4.1",
+    "version": "3.4.2",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",

packages/hydrooj/src/upgrade.ts

@@ -680,6 +680,7 @@ const scripts: UpgradeScript[] = [
         for (const task of tasks) {
             await TaskModel.add({ ...task, subType: 'contest', operation: ['unhide'] });
         }
+        await TaskModel.deleteMany({ type: 'schedule', subType: 'contest.problemHide' });
         return true;
     },
 ];