Fix lychee version check

[mondeja]

A change introduced in #279 triggers a weird error message. Check https://github.com/simple-icons/simple-icons/actions/runs/14554296040/job/40829177263#step:13:84

The problems are two as I can see:

• lychee --version | head -n1 | cut -d" " -f4 returns an empty string. It should be -f2 as the output of lychee --version is lychee <version>
• Semver comparisons are not possible using -lt in Bash. That raises an integer expression expected.

[mre]

Thanks for the fix @mondeja. ✌️

[mre]

@MrG9090, approvals on pull requests, please. It creates noise in the form of GitHub notifications.