Update vitest/expect dependency to latest major version

The latest version of `@vitest/expect` is now version `2.0.1` (coming
from `1.6.0`.

Author: stschulte

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Update `@vitest/expect` dependency to `2.0.1` (new major version)
+
 ## [3.0.0] - 2024-06-13
 
 ### Changed