Support resolving terraform version from config

I'm looking for a feature similar to `actions/setup-go@v5` https://github.com/actions/setup-go?tab=readme-ov-file#getting-go-version-from-the-gomod-file

If we could pass a `terraform-version-file` that takes a path to a `.tf` file containing the terraform block with `required_version` e.g.

**versions.tf**
```terraform
terraform {
required_version = "1.3.6"
}
```

*action*
```yaml
uses: hashicorp/setup-terraform@v3
with:
terraform-version-file: 'path/to/versions.tf'
```

Or better still just automatically find the .tf file with `required_version` config