EYQB-718 avoid deprecated terraform arguments

[RobertGHippo]

Description

While investigating SSL certificate auto-renewal and rotation, it might be appropriate to address our use of deprecated terraform arguments. This also probably requires a migration to a later version of terraform, which we should possibly do too as part of this.

Ticket number

EYQB-718

How Has This Been Tested?

Run terraform plan in GitHub.

Checklist:

• My code follows the standards used within this project
• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests (Unit, E2E) that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

Package	Line Rate	Branch Rate	Health
Dfe.EarlyYearsQualification.Mock	100%	98%	✔
Dfe.EarlyYearsQualification.Content	98%	90%	✔
Dfe.EarlyYearsQualification.Web	96%	90%	✔
Summary	97% (4120 / 4228)	91% (678 / 746)	✔

Minimum allowed line rate is 90%