* [refac] Remove explicit charset and collation declarations from SQL files

- Remove DEFAULT CHARSET declarations from all SQL table definitions
- Strip COLLATE clauses from field definitions across all database scripts
- Simplify ENGINE declarations by removing redundant charset specifications
- Standardize SQL statement formatting for improved database compatibility
- Affects all database update scripts from version 0.1 to 21.7.6

db/update4.3.sql

@@ -8,4 +8,4 @@ CREATE TABLE IF NOT EXISTS `zt_lang` (
   `system` enum('0','1') NOT NULL default '1',
   PRIMARY KEY  (`id`),
   UNIQUE KEY `lang` (`lang`,`module`,`section`,`key`)
-) ENGINE=MyISAM  DEFAULT CHARSET=utf8;
+) ENGINE=MyISAM;