Explain the view existence fallback for older REST catalogs

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: kevinjqliu

pyiceberg/catalog/rest/__init__.py

@@ -1796,6 +1796,7 @@ def view_exists(self, identifier: str | Identifier) -> bool:
         Returns:
             bool: True if the view exists, False otherwise.
         """
+        # fallback in order to work with older rest catalog implementations
         if Capability.V1_VIEW_EXISTS not in self._supported_endpoints:
             try:
                 self.load_view(identifier)