Check if `ga`-only logic can be removed from `iam_test_file.go.erb` file

[SarahFrench]

In Magic Modules' mmv1/templates/terraform/examples/base_configs/iam_test_file.go.erb file there's ga-only logic around import steps of acceptance tests and also around this code

<% unless object.min_version.name == "ga" -%>
		Providers:    testAccProvidersOiCS,
<% else -%>
		Providers:    testAccProviders,
<% end -%>

I think this can be removed as it originated a few years ago. This topic came up in another PR of mine (where I touched files for IAM test generation), but I think removing this logic is good to keep in a separate PR. Making this issue to keep track of this task