Update to terraform 1.9.6

[ocofaigh]

Description

Now that Schematics supports terraform 1.9, we can update our CI script to install it.
If any of our modules have issues on 1.9, the tests won't all of a sudden break, the renovate PR which updates the GIT submodule would fail the tests and we would catch it then.

I added a renovate rule which prevent the major and minor tf version from being updated.

I removed tofu from the dependency list - no plans to use it.

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