WithOSDetection: check for root privileges warning -- fix unclear error status

[tonymet]

Improve error handling when WithOSDetection is called without being root

Example Test CLI

https://gist.github.com/tonymet/6107b994863d8ba8f6e0c062ae026b27

git clone git@gist.github.com:6107b994863d8ba8f6e0c062ae026b27.git node-go-test
cd node-go-test
 go run . --target 192.168.10.1 
2025/01/04 17:21:09 unable to run nmap scan: this feature requires root privileges
2025/01/04 17:21:09 Warnings: 
 &[TCP/IP fingerprinting (for OS scan) requires root privileges.]
Nmap done: 0 hosts up scanned in 0.000000 seconds

STEPS TO REPEAT

1. create a scanner WithOSDetection() (see gist)
2. inspect err or warnings

	scanner, err := nmap.NewScanner(
		ctx,
		nmap.WithTargets(optTargets...),
		nmap.WithPorts(optPorts),
		nmap.WithOSDetection(),
	)

BEFORE

2025/01/04 17:15:08 unable to run nmap scan: exit status 1

AFTER

2025/01/04 17:15:28 unable to run nmap scan: this feature requires root privileges
2025/01/04 17:15:28 Warnings: 
 &[TCP/IP fingerprinting (for OS scan) requires root privileges.]

[tonymet]

excellent library. Very easy to work with , easy to patch

[Ullaakut]

Hi @tonymet , thanks for your contribution :) This looks good to me 👍

[Ullaakut]

Released as v3.0.5

[tonymet]

@Ullaakut thanks for the fantastic module and being an awesome maintainer. Happy to help out feel free to ping me if any other support work is needed.