Apply miscellaneous license detection updates

[pombredanne]

This PR contains various license detection updates for accuracy

Tasks

• Reviewed contribution guidelines
• PR is descriptively titled 📑 and links the original issue above 🔗
• Tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR
  Run tests locally to check for errors.
• Commits are in uniquely-named feature branch and has no merge conflicts 📁
• Updated documentation pages (if applicable)
• Updated CHANGELOG.rst (if applicable)

[pombredanne]

Same heisenbug as before:

             ERROR: Unknown error:
E               Traceback (most recent call last):
E                 File "/home/vsts/work/1/s/src/scancode/interrupt.py", line 89, in interruptible
E                   create_signal(SIGALRM, handler)
E                 File "/opt/hostedtoolcache/Python/3.10.15/x64/lib/python3.10/signal.py", line 56, in signal
E                   handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
E               ValueError: signal only works in main thread of the main interpreter

Merging as this is only on Azure pipelines