Support of OpenTofu grain

[shirabendor-quali]

Since Hashicorp announced the terraform licensing changes, we've been asked by customers to support OpenTofu.
OpenTofu is a fork of Terraform that is open-source, community-driven, and managed by the Linux Foundation and aims to replace terraform while preserving the open-source license.
Torque now supports OpenTofu grains for customers who wish to use it instead of Terraform.
Since it's fully compatible with terraform, we can support all the advanced capabilities which we have for terraform, such as policies, updates, pre-post scrips and more, just using the OpenTofu executable.

Use it like so:

The rest of the syntax is identical to the terraform grain syntax.