This is a followup to having tests run in serial in CI.
The e2e package isn't in CI, but lets use the helper anyway
so we can setup semgrep rules covering the entire repository.
The e2e test code is absolutely hideous and leaks processes and files
on disk. NomadAgent seems useful, but the clientstate e2e tests are very
messy and slow. The last test "Corrupt" is probably the most useful as
it explicitly corrupts the state file whereas the other tests attempt to
reproduce steps thought to cause corruption in earlier releases of
Nomad.
