Expand the scanning tools used for license detection for better coverage

In https://github.com/dotnet/source-build/issues/4590, a file that was originally thought to be acceptable for inclusion in the VMR for source build was discovered to be associated with a non-free license. A description for how this was found is here: https://github.com/dotnet/source-build/issues/4590#issuecomment-2329672636.

Today, we only use [scancode](https://github.com/aboutcode-org/scancode-toolkit) for detecting license references. It did not catch this case because the content of the binary file had no license reference. But the [lintian](https://manpages.ubuntu.com/manpages/oracular/en/man1/lintian.1.html) can match on checksums. We should consider expanding the set of tools used for license detection to get better coverage and catch cases like https://github.com/dotnet/source-build/issues/4590. The use of lintian may be a possibility but that requires the targeting of a DEB package, not arbitrary directories. We don't have DEB packages currently available at the time scanning takes place.