This is a latent issue that wasn't caught by CI because there was no
configuration that had both stackless+uasyncio.
The previous check to skip with stackless builds only worked when the
bytecode emitter was used by default. Force the check to use the bytecode
emitter.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Non-real-time systems like Windows, Linux and macOS do not have reliable
timing, so increase the sleep intervals to make these tests more likely to
pass.
Signed-off-by: Damien George <damien@micropython.org>