1 run ubysseyca and thothubysseyca as isolated apps on docker swarm vm

[Nishim12]

This pull request updates the deploy-production.yml GitHub Actions workflow to improve the deployment process by introducing job-level environment variables for Docker image tags, validating Docker images before deployment, and optimizing Docker image pulls and service updates. The changes aim to make the deployment more robust and efficient.

Deployment process improvements:

• Defined BACKEND_TAG and FRONTEND_TAG as job-level environment variables to simplify tag management throughout the deployment job.
• Added a validation step to check the existence of the specified backend and frontend Docker images before proceeding with deployment, preventing failures due to missing images.
• Optimized Docker image pulling by running backend and frontend image pulls in parallel on the production server, reducing deployment time.
• Added explicit Docker service updates for both backend and frontend services after deployment to ensure the latest images are used, even if the stack is already up.

Minor improvements:

• Switched from echo to printf when writing the SSH key file for better handling of newlines and formatting.