Skip yama/ptrace_scope check if unavailable in cuda-gdb attach

On CSCS systems (e.g. Piz Daint), there is no file

/proc/sys/kernel/yama/ptrace_scope

So attaching cuda-gdb to a running process with the Nsight VScode extension fails when trying to read this file. It can be fixed by first checking if it exists as in Comparing NVIDIA:master...lukasgd:piz_daint · NVIDIA/nsight-vscode-edition · GitHub.

Thanks for getting in touch. I will pass this information along to our debugger team. Is there anything else I can do for you on this issue?