The HashiCorp Terraform AWS provider has been updated to version 4.0, bringing significant usability improvements to data sources and attribute validations, as well as a refactored S3 bucket resource. The new version includes four major updates: updating the Amazon S3 bucket resource, implementing the full CRUD lifecycle for default resources, ensuring all plural data sources return zero results, and improving provider configuration. These changes aim to simplify configurations and improve the overall experience of using the Terraform AWS provider, with features such as a refactored S3 bucket management resource, improved fine-grained identity and access management, and support for FIPS, DualStack, unique STS regions, and multiple shared credentials files. The update also includes additional resources and recommendations for practitioners to transition smoothly to the new version.