chore: allow storing resource references >256 chars long in mysql (#4408)

fix: allow storing resource references >256 chars long in mysql

store/migration/mysql/0.25/00__s3_reference_length.sql

+-- https://github.com/usememos/memos/issues/4322
+
+ALTER TABLE `resource` MODIFY `reference` TEXT NOT NULL DEFAULT ('');

store/migration/mysql/LATEST.sql

@@ -77,7 +77,7 @@ CREATE TABLE `resource` (
   `size` INT NOT NULL DEFAULT '0',
   `memo_id` INT DEFAULT NULL,
   `storage_type` VARCHAR(256) NOT NULL DEFAULT '',
-  `reference` VARCHAR(256) NOT NULL DEFAULT '',
+  `reference` TEXT NOT NULL DEFAULT (''),
   `payload` TEXT NOT NULL
 );