Do not pollute all CI with Terraform stuff

What does this MR do and why?

Before this patch, if a project included terraform instructions and other things, including the terraform base would pollute all other jobs configuration.

Now all terraform jobs extend the .terraform one.

This lets you customize all terraform jobs all at once, while letting the global namespace unpolluted for other usages.

Screenshots or screen recordings

N/A

How to set up and validate locally

All your terraform jobs should work just like before.

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.