pkg: don't silently skip non %tests/ test arms
No longer strips "%tests" from the beginning of test filepaths.
Fixes [#5803](https://github.com/urbit/urbit/issues/5803)
%+ turn ~(tap by paths-to-tests)
|= [=path test-arms=(list test-arm)]
^- (list test)
- :: strip off leading 'tests' from :path
- ::
- ?. ?=([%tests *] path) ~
- =/ path t.path ::NOTE TMI
:: for each test, add the test's name to :path
::
%+ turn test-arms
