Migrate from tfenv to tenv

[kvendingoldo]

Hi! I saw that you're using tfenv in this repository. It's a really good tool, but it does not support OpenTofu and Terragrunt. My team designed a successor of tenv that support Terraform, Terragrunt and OpenTofu. It will be a good idea to migrate into it in due to the growing popularity of OpenTofu.
url: https://github.com/tofuutils/tenv