This fixes a bug where some packages tests run twice in CI, because they
are subpackages of ones with dedicated jobs.  For example, notice
`client/allocrunner` tests ran in `test-client`[1] and `test-other`[2] despite
them being in the same workflow[3].

[1] https://circleci.com/gh/hashicorp/nomad/5262
[2] https://circleci.com/gh/hashicorp/nomad/5261
[3] https://circleci.com/workflow-run/ee7a9167-8fc7-49a5-897c-6c967e966014