v2.0.0 remove experiment optional attribute

Terraform v0.14.0 introduced a new experimental language feature for declaring object type constraints with optional attributes in your module's input variables. Thanks to feedback from those who tried the experiment, a refinement of that functionality is now stablized in Terraform v1.3

https://www.terraform.io/language/upgrade-guides#concluding-the-optional-attributes-experiment

What's Changed

• [v2.0.0] remove experiment optional attributes by @bryan-rhm in #2

Full Changelog: v1.0.0...v2.0.0