Attempt to fix unwanted position update

The function position_changed? returns true even if the position remains the same. This because the corresponding method on the @positioned (`@positioned.position_changed?`) returns true (at least on my 7.1.3.2 version of ActiveRecord).

lib/positioning/mechanisms.rb

@@ -117,7 +117,8 @@ def solidify_position
 
       case position_before_type_cast
       when Integer
-        self.position = position_before_type_cast.clamp(1..last_position)
+        clamped_position = position_before_type_cast.clamp(1..last_position)
+        self.position = clamped_position unless self.position == clamped_position
       when :first, {after: nil}, {after: ""}
         self.position = 1
       when nil, "", :last, {before: nil}, {before: ""}