Fix Message.date timezone conversion causing logical errors in time comparison (#193)

* Fix timestamp_to_datetime to correctly handle timezone conversion

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: Copilot

pyrogram/utils.py

@@ -466,7 +466,7 @@ def zero_datetime() -> datetime:
 
 
 def timestamp_to_datetime(ts: Optional[int]) -> Optional[datetime]:
-    return datetime.fromtimestamp(ts).replace(tzinfo=timezone.utc) if ts else None
+    return datetime.fromtimestamp(ts, tz=timezone.utc) if ts else None
 
 
 def datetime_to_timestamp(dt: Optional[datetime]) -> Optional[int]: