feat: add __int__ method to Timestamp class

Author: AutonomousCat

interactions/models/discord/timestamp.py

@@ -163,3 +163,6 @@ def format(self, style: Optional[Union[TimestampStyles, str]] = None) -> str:
 
     def __str__(self) -> str:
         return self.format()
+    
+    def __int__(self) -> int:
+        return int(self.timestamp())