Analyzer::Go::GoTestPath
GoEngine.go_test_file? judged from the file's own module. Go's _ and
testdata exclusions are relative to the module, and a nested module is
its own root: chi's _examples/rest/go.mod builds _examples/rest as an
ordinary package, so its routes count whether the scan starts at the repo
or at _examples. Included by every Go analyzer, engine or not.