A thread made inside a test does not share the test index of its parent,
so any time one of those threads failed an assert, it would tell the
runner to shutdown test index zero.
Currently, a Ctrl+c starts a graceful shutdown of the tests and runner.
Sometimes tests get stuck and this would never complete.
This simply adds an extra step, if Ctrl+c is given for the second time,
just `os.exit` right away.
Karl Zylinski
Feoramund
Laytan Laats