Remove unnecessary access modifier in interface

Co-authored-by: Dan Balasescu <smoogipoo@smgi.me>

osu.Game/Rulesets/IRulesetInfo.cs

@@ -28,7 +28,7 @@ namespace osu.Game.Rulesets
         /// </summary>
         string InstantiationInfo { get; }
 
-        public Ruleset? CreateInstance()
+        Ruleset? CreateInstance()
         {
             var type = Type.GetType(InstantiationInfo);