🔧 DAT-18919: fossa report generation

[sayaliM0412]

This pull request includes significant updates to the FOSSA report generation workflows. The changes involve renaming workflows, updating event triggers, modifying job steps, and adding new workflows for better management and report generation. Below are the most important changes:

Workflow Updates and Enhancements:

• .github/workflows/fossa.yml: Renamed the workflow to "Enterprise- FOSSA Report Generation", updated event triggers, and restructured the job steps to include a matrix strategy for handling multiple repositories. Added steps to handle retry logic for fetching run IDs and combining FOSSA reports.
• .github/workflows/generate-upload-fossa-report.yml: Created a new workflow for generating and uploading FOSSA reports to S3. This workflow includes steps for setting up the environment, analyzing the project, generating reports, and uploading them to S3.

Configuration and Dependency Management:

• .github/workflows/ignore_dependencies_fossa.txt: Added a list of dependencies to be ignored during FOSSA report generation.

Environment Variable Handling:

• .github/workflows/package.yml: Updated the handling of environment variables for checking the existence of a pull request. The environment variable PR_EXISTS is now set directly in the GitHub environment.

Documentation:

• README.md: Added a new section detailing the process for FOSSA report generation for enterprise, including steps for running workflows and handling report uploads.