Change PER ruleset (#4)

Rule set "@PER-CS3.0" is deprecated. Use "@PER-CS3x0" instead.

Author: ruudk

src/RuleSet/TicketSwapRuleSet.php

@@ -65,7 +65,7 @@ public static function create() : RuleSet
             ),
             new Rules([
                 // Rule sets
-                '@PER-CS3.0' => true,
+                '@PER-CS3x0' => true,
 
                 // Rules (keep sorted A-Z)
                 'align_multiline_comment' => true,