fix: handle Z suffix in fromisoformat for Python 3.10 compatibility

Author: boutetnico

src/rdapapi/models.py

@@ -53,7 +53,7 @@ def _parse(value: Optional[str]) -> Optional[datetime]:
         if value is None:
             return None
         try:
-            return datetime.fromisoformat(value)
+            return datetime.fromisoformat(value.replace("Z", "+00:00"))
         except (ValueError, TypeError):
             return None