docs: remove FOSSA in README.md

[gaius-qi]

Description

This pull request involves a minor change to the README.md file. The change removes the License section and the associated FOSSA status badge.

• README.md: Removed the License section and the FOSSA status badge.

Related Issue

Motivation and Context

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[chlins]

lgtm