fix: don't link artifacts in tests

the crane changelog states:

> inheritCargoArtifactsHook will now symlink dependency .rlib and .rmeta
  files. This means that derivations which reuse existing cargo artifacts
  will run faster as fewer files (and bytes!) need to be copied around.
  To disable this behavior, set doNotLinkInheritedArtifacts = true;.

since we never use the artifacts of tests, this can be disabled.