Deploy `mainnet` infrastructure

[jpraynaud]

Issue

Deploy the release-mainnet network in GCP

To do

• [x] Setup new mithril project in GCP
  • [x] Configure service account
  • [x] Activate services used by the Mithril network
• [x] Configure monitoring/alerting with Grafana Cloud for release-mainnet (IT Ticket to create)
• [x] Setup release-mainnet network
• [x] Wire release-mainnet network in CD workflow
• [x] Update networks matrix in documentation

Parent Issue

767

[roynakakawa]

Ticket https://input-output.atlassian.net/servicedesk/customer/portal/2/ITCR-6365?created=true