terraform: add audit for relicensing

[iMichka]

See also
Homebrew/homebrew-core#139538

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
• Have you successfully run brew typecheck with your changes locally?
• Have you successfully run brew tests with your changes locally?

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[MikeMcQuaid]

Thanks again @iMichka!

[p-linnane]

We will need to do this for the rest of the affected HashiCorp products as well.

[ZhongRuoyu]

We will need to do this for the rest of the affected HashiCorp products as well.

Doing this in #15982.