[2151] Github actions OIDC

[saliceti]

Context

Stop using service principal secrets and use OIDC instead

Changes proposed in this pull request

• Replace secrets with federated credentials in workflows
• Replace secrets with federated credentials in kubernetes terraform
• Add deployment smoke test
• Refactor domains configuration to use the same environments and federated credentials
• The federated credentials have been created in each service principal
• Github environment variables have been created to enable the smoke test in platform-test and test

Guidance to review

Deployment workflow with OIDC in all environments: https://github.com/DFE-Digital/teacher-services-cloud/actions/runs/12689712811
The deployment smoke test runs in platform-test and test

After merging

Delete service principal secrets

Checklist

• I have performed a self-review of my code, including formatting and typos
• I have cleaned the commit history
• I have added the Devops label
• I have attached the pull request to the trello card