fix(deps): update module github.com/hashicorp/terraform-plugin-testing to v1.12.0#724

bahkauv70 merged 2 commits intomainstackitcloud/terraform-provider-stackit:mainfrom

renovate/github.com-hashicorp-terraform-plugin-testing-1.xstackitcloud/terraform-provider-stackit:renovate/github.com-hashicorp-terraform-plugin-testing-1.xCopy head branch name to clipboard