fix: update pinned column value in down migration

src/util/migration/postgres/1752383879533-message_pinned_at.ts

@@ -18,5 +18,8 @@ export class MessagePinnedAt1752383879533 implements MigrationInterface {
 			`ALTER TABLE "messages" DROP COLUMN "pinned_at"`,
 		);
 		await queryRunner.query(`ALTER TABLE "messages" ADD "pinned" boolean`);
+		await queryRunner.query(
+			`UPDATE "messages" SET "pinned" = true WHERE "pinned_at" IS NOT NULL`,
+		);
 	}
 }