get hints from strictures as late as possible
strictures v1 enables all fatal warnings, which included anything custom
registered by other modules. Moo will delay loading modules for as long
as possible, which means some things, like Class::Method::Modifiers,
won't be loaded until the WithHintPersistence role is applied at object
creation time. This may what causes vars.pm to be loaded, which
registers a warning category and can break the test.
If we delay checking the expected hints until immediately before going
the eval test, all warning categories should be loaded.