This is one of the many things where Go just takes care of automatically. Since Go 1.19, if you import the os package, on startup, the open file soft limit will be raised to the hard limit: https://github.com/golang/go/commit/8427429c592588af8c49522c...
Seems like a good idea but I do wonder what the cost is as the overhead of allocate the extra resource space (whatever it is) would be added to every Go application.
I doubt the kernel would actually allocate the resource space upfront. Like SO_SNDBUF and SO_RCVBUF, it's probably only allocated when it's actually needed.