Fix: Ensure config parameter is always passed to sync()

The sync() function requires config as a parameter even when None.
Update the kwargs filtering to always include config in the allowed
parameters list.

Author: tony

src/vcspull/cli/__init__.py

@@ -152,7 +152,7 @@ def cli(_args: list[str] | None = None) -> None:
         sync_kwargs = {
             k: v
             for k, v in sync_kwargs.items()
-            if v is not None or k in {"parser", "exit_on_error"}
+            if v is not None or k in {"parser", "exit_on_error", "config"}
         }
         sync(**sync_kwargs)
     elif args.subparser_name == "add":