fix(permissions): don't require --allow-run for process.kill on self (#34382)
Sending a signal to the current process is functionally equivalent to
terminating yourself, which never required permissions in the first
place (`Deno.exit`, abort, etc.). Tools like `signal-exit` (used by
vite and many others) re-raise the original signal on `process.pid` so
the parent shell sees the correct exit status, which forced users to
grant blanket `--allow-run` just to be able to Ctrl-C a process.
This skips the run-permission check in `op_node_process_kill` and
`op_kill` when the target pid is the current process's pid. Signalling
any other pid still requires `--allow-run` as before.
Fixes #34344