This PR removes APIScan for the ripgrep-prebuilt pipeline considering that:

1. We have already handled APIScan results for ripgrep-prebuilt.
2. The ADO organization in which the pipeline runs does not support a WIF Service Connection to APIScan.
3. The only file to scan is rg.exe, which is a Rust binary. APIScan currently does not support Rust binaries, anyway, meaning it would be more appropriate for us to periodically manually review the upstream project and its HVP calls.