Fix link checks on main

[trask]

https://github.com/open-telemetry/opentelemetry-java-instrumentation/actions/runs/19641848122/job/56247114893

fatal: ambiguous argument 'origin/': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'