Refactor CI/CD workflow to capture primary image reference and update output variable for Docker image tagging

Update CI/CD workflow to improve Docker image handling and add GitHub Container Registry login step

Fix casing in Trivy scanner image reference to ensure proper functionality

Update Trivy scanner image reference to use lowercase repository owner

Update CI/CD workflow and remove deprecated app.py and test_app.py

Implement code structure updates and remove redundant sections

Added CI/CD pipeline configuration