v1.2.0

• Clean up dependencies and test against newer PHP versions
• BC break: Require PHP 8.1 or newer
• Minor BC break: Key is now using readonly properties - the getters have been removed
• Minor BC break: RequestSigner no longer accepts null for $digest - omit this parameter or pass an instance of Digest if you don't want to customize it.
• Minor BC break: All properties are now typed, including protected ones. If you happen to override them, make sure to update the types too.