Seems that on 3.13 it's not showing our script code in the output now?
Gotta get an example for @oremanj to see what's up but really it'd be
nice to just custom format stuff above `trio`'s runtime by def..
Anyway, update the `.devx._stackscope`,
- log formatting to be a little more "sclangy" lookin.
- change the per-actor "delimiter" lines style.
- report the `signal.getsignal(SIGINT)` which i needed in the
`sync_bp.py` with ctl-c causing a hang..
- mask the `_tree_dumped` duplicator log report as well as the "dumped
fine" one.
- add an example `pkill --signal SIGUSR1` cmdline.
Tweak the test to cope with,
- not showing our script lines now.. which i've commented in the
`assert_before()` patts..
- to expect the newly formatted delimiter (ascii) lines to separate the
root vs. hanger sub-actor sections.