Support ability to pass `--unsafe` to bpftrace

[yuvipanda]

LOVE THE PROJECT!

I want to use signal calls in my bpftrace programs, but I think you need to pass --unsafe to bpftrace to enable that. Right now, if I use a signal call in my bpftrace program and run it with kubectl trace run, the pod just goes into 'completed' state fast enough I can't even get logs out. My guess (since the same program works without the signal) is that this is due to lack of the --unsafe flag. Would love for the ability to pass this flag through.