Treat leading option-like subcommand tokens as passthrough args.
Click stores the unresolved nested command token on the context after
Group.parse_args() runs, but the backing attribute changed across
supported Click versions. Click 8.1.x stores the value directly on
protected_args, while Click 8.2+ stores it on _protected_args
and exposes protected_args as a deprecated compatibility property.
Since this package allows click>=8.1.7, we need to check both
names to support the full version range without relying on one
version-specific internal detail.
