feat: change function property to cached_property for performance improvement

Author: SunBK201

scubatrace/statement.py

@@ -258,7 +258,7 @@ def file(self) -> File:
             return self.parent
         return self.parent.file
 
-    @property
+    @cached_property
     def function(self) -> Function | None:
         """
         The function this statement belongs to, if any.