Legacy license compliance widget removal

What does this MR do and why?

As a follow up to #367703 (closed)

This removes the feature flag code.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

How to set up and validate locally

• Reach out to me for a demo, or attempt steps below
• Clone the https://gitlab.com/gitlab-examples/security/security-reports project locally
• Manually trigger the pipeline to run for Master. This can be done by going to the CI/CD -> Pipelines tab on the left nav and then clicking the Run Pipeline button.
• Set up Allowed/Denied licenses in https://<localhost>/<group>/<project>/-/licenses#policies
• Create a new MR. I suggest changing something simple like a letter or two in the README.md file. We just need a pipeline to complete and run. The sample project uses test reports to generate the data so doesn't matter what you change just need a MR.
• Go to the MR and look for the license compliance widget.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #367704 (closed)