* config: The `list` and `map` functions, both of which were deprecated since Terraform v0.12, are now removed. You can replace uses of these functions with `tolist([...])` and `tomap({...})` respectively. [GH-26818]
* cli: Interrupting execution will now cause terraform to exit with a non-0 status. [GH-26738]
* backend/atlas: the `atlas` backend, which was deprecated since v0.12, has been removed. [GH-26651]
* cli: The family of error messages with the summary "Invalid for_each argument" will now include some additional context about which external values contributed to the result. [GH-26747]
* cli: Exit with an error if unable to gather input from the UI. For example, this may happen when running in a non-interactive environment but without `-input=false`. Previously Terraform would interpret these errors as empty strings, which could be confusing. [GH-26509]