Remove expectation of process exit in test body (dart-lang/test_process#43)

Closes dart-lang/test_process#31

This check does not seem to serve a useful purpose - most tests which
care about the process existing will already be using `shouldExit`.
Since we have a `kill` in the teardown, we may as well not force the
test to timeout before hitting it.
4 files changed
tree: 748a64f77046e2f923350c07aa1e8e93ae4bdcd7
  1. pkgs/