Experiment "module_variable_optional_attrs" is no longer available

[steml-orsted]

Hi,
Running terraform 1.3.9, terraform init fails with the following:
terraform init
Initializing modules...
Downloading registry.terraform.io/kumarvna/redis/azurerm 1.0.0 for landingzone.redis...

• landingzone.redis in .terraform/modules/landingzone.redis
  There are some problems with the configuration, described below.

The Terraform configuration must be valid before initialization so that
Terraform can determine which modules and providers need to be installed.
╷
│ Error: Experiment has concluded
│
│ on .terraform/modules/landingzone.redis/versions.tf line 2, in terraform:
│ 2: experiments = [module_variable_optional_attrs]
│
│ Experiment "module_variable_optional_attrs" is no longer available. The final feature corresponding to this
│ experiment differs from the experimental form and is available in the Terraform language from Terraform v1.3.0
│ onwards.