[DevOps] Scale down fly instances to 0 for production server

[jji05]

Is your feature request related to a problem? Please describe.

Cut costs and no need for it. Need to modify fly IaC.

BEFORE MERGING

• Acceptance criteria met
• PR Reviewed (For non-trivial changes)
• Changes tested after rebasing on master or merging in master (hint: git fetch origin master:master, then git rebase master or git merge master)
• All required PR checks passing